Ultrasonic surgical instrument with opposing thread drive for end effector articulation

ABSTRACT

An apparatus comprises a body assembly, a shaft assembly, an end effector, an articulation section, and an articulation control assembly. The end effector is located at a distal end of the shaft assembly and comprises an ultrasonic blade. The articulation section is coupled with the shaft assembly and is operable to articulate to thereby deflect the end effector from the longitudinal axis. The articulation control assembly comprises first and second threaded members and an articulation control. The first and second threaded members have respective first and second pitch orientations. The articulation control is rotatable to thereby drive articulation of the articulation section by causing translation of the first and second threaded members along a path that is parallel to the longitudinal axis of the shaft assembly. The axis of rotation of the articulation control is non-parallel with the longitudinal axis of the shaft assembly.

BACKGROUND

A variety of surgical instruments include an end effector having a bladeelement that vibrates at ultrasonic frequencies to cut and/or sealtissue (e.g., by denaturing proteins in tissue cells). These instrumentsinclude piezoelectric elements that convert electrical power intoultrasonic vibrations, which are communicated along an acousticwaveguide to the blade element. The precision of cutting and coagulationmay be controlled by the surgeon's technique and adjusting the powerlevel, blade edge, tissue traction and blade pressure.

Examples of ultrasonic surgical instruments include the HARMONIC ACE®Ultrasonic Shears, the HARMONIC WAVE® Ultrasonic Shears, the HARMONICFOCUS® Ultrasonic Shears, and the HARMONIC SYNERGY® Ultrasonic Blades,all by Ethicon Endo-Surgery, Inc. of Cincinnati, Ohio. Further examplesof such devices and related concepts are disclosed in U.S. Pat. No.5,322,055, entitled “Clamp Coagulator/Cutting System for UltrasonicSurgical Instruments,” issued Jun. 21, 1994, the disclosure of which isincorporated by reference herein; U.S. Pat. No. 5,873,873, entitled“Ultrasonic Clamp Coagulator Apparatus Having Improved Clamp Mechanism,”issued Feb. 23, 1999, the disclosure of which is incorporated byreference herein; U.S. Pat. No. 5,980,510, entitled “Ultrasonic ClampCoagulator Apparatus Having Improved Clamp Arm Pivot Mount,” filed Oct.10, 1997, the disclosure of which is incorporated by reference herein;U.S. Pat. No. 6,325,811, entitled “Blades with Functional BalanceAsymmetries for use with Ultrasonic Surgical Instruments,” issued Dec.4, 2001, the disclosure of which is incorporated by reference herein;U.S. Pat. No. 6,773,444, entitled “Blades with Functional BalanceAsymmetries for Use with Ultrasonic Surgical Instruments,” issued Aug.10, 2004, the disclosure of which is incorporated by reference herein;U.S. Pat. No. 6,783,524, entitled “Robotic Surgical Tool with UltrasoundCauterizing and Cutting Instrument,” issued Aug. 31, 2004, thedisclosure of which is incorporated by reference herein; U.S. Pat. No.8,461,744, entitled “Rotating Transducer Mount for Ultrasonic SurgicalInstruments,” issued Jun. 11, 2013, the disclosure of which isincorporated by reference herein; U.S. Pat. No. 8,591,536, entitled“Ultrasonic Surgical Instrument Blades,” issued Nov. 26, 2013, thedisclosure of which is incorporated by reference herein; and U.S. Pat.No. 8,623,027, entitled “Ergonomic Surgical Instruments,” issued Jan. 7,2014, the disclosure of which is incorporated by reference herein.

Still further examples of ultrasonic surgical instruments are disclosedin U.S. Pub. No. 2006/0079874, entitled “Tissue Pad for Use with anUltrasonic Surgical Instrument,” published Apr. 13, 2006, the disclosureof which is incorporated by reference herein; U.S. Pub. No.2007/0191713, entitled “Ultrasonic Device for Cutting and Coagulating,”published Aug. 16, 2007, the disclosure of which is incorporated byreference herein; U.S. Pub. No. 2007/0282333, entitled “UltrasonicWaveguide and Blade,” published Dec. 6, 2007, the disclosure of which isincorporated by reference herein; U.S. Pub. No. 2008/0200940, entitled“Ultrasonic Device for Cutting and Coagulating,” published Aug. 21,2008, the disclosure of which is incorporated by reference herein; andU.S. Pub. No. 2010/0069940, entitled “Ultrasonic Device for FingertipControl,” published Mar. 18, 2010, the disclosure of which isincorporated by reference herein.

Some ultrasonic surgical instruments may include a cordless transducersuch as that disclosed in U.S. Pub. No. 2012/0112687, entitled “RechargeSystem for Medical Devices,” published May 10, 2012, the disclosure ofwhich is incorporated by reference herein; U.S. Pub. No. 2012/0116265,entitled “Surgical Instrument with Charging Devices,” published May 10,2012, the disclosure of which is incorporated by reference herein;and/or U.S. Pat. App. No. 61/410,603, filed Nov. 5, 2010, entitled“Energy-Based Surgical Instruments,” the disclosure of which isincorporated by reference herein.

Additionally, some ultrasonic surgical instruments may include anarticulating shaft section and/or a bendable ultrasonic waveguide.Examples of such ultrasonic surgical instruments are disclosed in U.S.Pat. No. 5,897,523, entitled “Articulating Ultrasonic SurgicalInstrument,” issued Apr. 27, 1999, the disclosure of which isincorporated by reference herein; U.S. Pat. No. 5,989,264, entitled“Ultrasonic Polyp Snare,” issued Nov. 23, 1999, the disclosure of whichis incorporated by reference herein; U.S. Pat. No. 6,063,098, entitled“Articulable Ultrasonic Surgical Apparatus,” issued May 16, 2000, thedisclosure of which is incorporated by reference herein; U.S. Pat. No.6,090,120, entitled “Articulating Ultrasonic Surgical Instrument,”issued Jul. 18, 2000, the disclosure of which is incorporated byreference herein; U.S. Pat. No. 6,454,782, entitled “Actuation Mechanismfor Surgical Instruments,” issued Sep. 24, 2002, the disclosure of whichis incorporated by reference herein; U.S. Pat. No. 6,589,200, entitled“Articulating Ultrasonic Surgical Shears,” issued Jul. 8, 2003, thedisclosure of which is incorporated by reference herein; U.S. Pat. No.6,752,815, entitled “Method and Waveguides for Changing the Direction ofLongitudinal Vibrations,” issued Jun. 22, 2004, the disclosure of whichis incorporated by reference herein; U.S. Pat. No. 7,135,030, entitled“Articulating Ultrasonic Surgical Shears,” issued Nov. 14, 2006; U.S.Pat. No. 7,621,930, entitled “Ultrasound Medical Instrument Having aMedical Ultrasonic Blade,” issued Nov. 24, 2009, the disclosure of whichis incorporated by reference herein; U.S. Pub. No. 2014/0005701,published Jan. 2, 2014, entitled “Surgical Instruments with ArticulatingShafts,” the disclosure of which is incorporated by reference herein;U.S. Pub. No. 2014/005703, entitled “Surgical Instruments withArticulating Shafts,” published Jan. 2, 2014, the disclosure of which isincorporated by reference herein; U.S. Pub. No. 2014/0114334, entitled“Flexible Harmonic Waveguides/Blades for Surgical Instruments,”published Apr. 24, 2014, the disclosure of which is incorporated byreference herein; U.S. Pub. No. 2015/0080924, entitled ““ArticulationFeatures for Ultrasonic Surgical Instrument,” published Mar. 19, 2015,the disclosure of which is incorporated by reference herein; and U.S.patent application Ser. No. 14/258,179, entitled Ultrasonic SurgicalDevice with Articulating End Effector,” filed Apr. 22, 2014, thedisclosure of which is incorporated by reference herein.

While several surgical instruments and systems have been made and used,it is believed that no one prior to the inventors has made or used theinvention described in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims which particularly pointout and distinctly claim this technology, it is believed this technologywill be better understood from the following description of certainexamples taken in conjunction with the accompanying drawings, in whichlike reference numerals identify the same elements and in which:

FIG. 1 depicts a side elevational view of an exemplary ultrasonicsurgical instrument;

FIG. 2 depicts a perspective view of an articulation section of a shaftassembly and an end effector of the surgical instrument of FIG. 1;

FIG. 3 depicts an exploded perspective view of an articulation sectionof the shaft assembly of FIG. 2;

FIG. 4 depicts a cross-sectional side view of the shaft assembly and endeffector of FIG. 2;

FIG. 5 depicts a top plan view of the shaft assembly and end effector ofFIG. 2;

FIG. 6A depicts a cross-sectional top view of the shaft assembly and endeffector of FIG. 2 in a straight configuration;

FIG. 6B depicts a cross-sectional top view of the shaft assembly and endeffector of FIG. 2 in an articulated configuration;

FIG. 7 depicts a partially exploded perspective view of the shaftassembly and end effector of FIG. 2;

FIG. 8 depicts a perspective view of a distal collar and a drive cableof the shaft assembly of FIG. 2;

FIG. 9 depicts a partially exploded perspective view of an articulationcontrol assembly of the instrument of FIG. 1;

FIG. 10A depicts a side elevational view of an exemplary alternative endeffector and the distal portion of a shaft assembly, configured forincorporation in the instrument of FIG. 1, with a clamp arm of the endeffector in a closed position, and with an outer sheath shown incross-section to reveal components within the outer sheath;

FIG. 10B depicts a side elevational view of the shaft assembly and endeffector of FIG. 10A, with the clamp arm moved to a partially openposition;

FIG. 10C depicts a side elevational view of the shaft assembly and endeffector of FIG. 10A, with the clamp arm moved to a fully open position;

FIG. 11 depicts a side elevational view of another exemplary ultrasonicsurgical instrument;

FIG. 12 depicts a perspective view of the instrument of FIG. 11;

FIG. 13 depicts a side elevational view of a proximal portion of theinstrument of FIG. 11 with a shrouding half removed;

FIG. 14 depicts a detailed side elevational view of the instrument ofFIG. 11 with a shrouding half removed;

FIG. 15 depicts a cross-sectional front view of a shaft assembly of theinstrument of FIG. 11;

FIG. 16 depicts a perspective view of internal components of the shaftassembly of FIG. 15;

FIG. 17 depicts a partially exploded perspective view of an articulationcontrol assembly of the instrument of FIG. 11;

FIG. 18 depicts an exploded perspective view of a drive assembly of thearticulation control assembly of FIG. 17;

FIG. 19 depicts another partially exploded perspective view of the driveassembly of FIG. 18;

FIG. 20 depicts a perspective view of a lead screw of the drive assemblyof FIG. 18;

FIG. 21 depicts a front elevational view of the lead screw of FIG. 20;

FIG. 22 depicts a perspective view of another lead screw of the driveassembly of FIG. 18;

FIG. 23 depicts a front elevational view of the lead screw of FIG. 22;

FIG. 24A depicts a perspective view of a cylindrical guide of the driveassembly of FIG. 18;

FIG. 24B depicts a partially exploded perspective view of thecylindrical guide of FIG. 24A;

FIG. 25 depicts a cross-sectional perspective view of the drive assemblyof FIG. 18, taken along the line 25-25 of FIG. 19;

FIG. 26 depicts a cross-sectional perspective view of the drive assemblyof FIG. 18, taken along the line 26-26 of FIG. 19;

FIG. 27A depicts a detailed side elevational view of the instrument ofFIG. 11 with a shrouding half removed, and a cross-sectional top view ofan articulation section of the shaft assembly of FIG. 15, with thearticulation section in a substantially straight configuration;

FIG. 27B depicts a detailed side elevational view of the instrument ofFIG. 11 with a shrouding half removed, and a cross-sectional top view ofthe articulation section of FIG. 27A, with the articulation section in afirst stage of articulation;

FIG. 27C depicts a detailed side elevational view of the instrument ofFIG. 11 with a shrouding half removed, and a cross-sectional top view ofthe articulation section of FIG. 27A, with the articulation section in asecond stage of articulation;

FIG. 28 depicts a side elevational view of yet another exemplaryultrasonic surgical instrument;

FIG. 29 depicts a perspective view of the instrument of FIG. 28;

FIG. 30 depicts a perspective view of the instrument of FIG. 28, with adisposable portion separated from a reusable portion;

FIG. 31 depicts a perspective view of an exemplary alternativedisposable portion that may be used with the reusable portion of theinstrument of FIG. 28;

FIG. 32 depicts another perspective view the disposable portion of FIG.31;

FIG. 33 depicts a cross-sectional front view of a shaft assembly of thedisposable portion of FIG. 31, taken along line 33-33 of FIG. 31;

FIG. 34 depicts another cross-sectional front view of a shaft assemblyof the disposable portion of FIG. 31, taken along line 34-34 of FIG. 31;

FIG. 35 depicts a perspective view of internal components of the shaftassembly of FIG. 34;

FIG. 36 depicts a side elevational view of a body portion of thedisposable portion of FIG. 31;

FIG. 37 depicts a side elevational view of the body portion of FIG. 36with a shrouding half removed;

FIG. 38 depicts a detailed side elevational view of the body portion ofFIG. 36 with a shrouding half removed;

FIG. 39 depicts a side elevational view of an articulation controlassembly of the disposable portion of FIG. 31;

FIG. 40 depicts a perspective view of the articulation control assemblyof FIG. 39;

FIG. 41A depicts a partially exploded side elevational view of thearticulation control assembly of FIG. 39;

FIG. 41B depicts a perspective view of a gear reduction assembly of thearticulation control assembly of FIG. 39;

FIG. 41C depicts an exploded perspective view of the gear reductionassembly of FIG. 41B;

FIG. 41D depicts a perspective view of a bevel gear of the gearreduction assembly of FIG. 41B;

FIG. 41E depicts a front elevational view of the bevel gear of FIG. 41D;

FIG. 41F depicts a perspective view of a fixed spline member of the gearreduction assembly of FIG. 41B;

FIG. 41G depicts a rear elevational view of the fixed spline member ofFIG. 41F;

FIG. 41H depicts a perspective view of a flex spline member of the gearreduction assembly of FIG. 41B;

FIG. 41I depicts a rear elevational view of the flex spline member ofFIG. 41H;

FIG. 41J depicts a cross-sectional view of the gear reduction assemblyof FIG. 41B, taken along line 41J-41J of FIG. 41B;

FIG. 42 depicts a partial cross-sectional perspective view of a driveassembly of the articulation control assembly of FIG. 39;

FIG. 43 depicts a perspective view of a cylindrical guide of the driveassembly of FIG. 42;

FIG. 44 depicts a perspective view of a proximal rotatable housing ofthe drive assembly of FIG. 42;

FIG. 45 depicts a front elevational view of the proximal rotatablehousing of FIG. 44;

FIG. 46 depicts a cross-sectional side view of the proximal rotatablehousing of FIG. 44;

FIG. 47 depicts another cross-sectional side view of the proximalrotatable housing of FIG. 44;

FIG. 48 depicts a perspective view of a lead screw of the drive assemblyof FIG. 42;

FIG. 49 depicts a front elevational view of the lead screw of FIG. 48;

FIG. 50 depicts a side elevational view of the lead screw of FIG. 48;

FIG. 51 depicts a perspective view of a translatable assembly of thedrive assembly of FIG. 42;

FIG. 52 depicts a cross-sectional perspective view of the translatableassembly of

FIG. 51, taken along line 52-52 of FIG. 51;

FIG. 53 depicts a cross-sectional rear view of the drive assembly ofFIG. 42;

FIG. 54 depicts a perspective view of a distal rotatable housing of thedrive assembly of FIG. 42;

FIG. 55 depicts a side elevational view of the distal rotatable housingof FIG. 54;

FIG. 56 depicts a front elevational view of the distal rotatable housingof FIG. 54;

FIG. 57 depicts a cross-sectional side view of the distal rotatablehousing of FIG. 54, taken along line 57-57 of FIG. 54;

FIG. 58 depicts another cross-sectional side view of the secondrotatable housing of FIG. 54, taken along line 58-58 of FIG. 54;

FIG. 59 depicts a perspective view of another lead screw of the driveassembly of FIG. 42;

FIG. 60 depicts a front elevational view of the lead screw of FIG. 59;

FIG. 61 depicts a bottom plan view of the lead screw of FIG. 59;

FIG. 62 depicts a perspective view of yet another lead screw of thedrive assembly of FIG. 42;

FIG. 63 depicts a front elevational view of the lead screw of FIG. 62;

FIG. 64 depicts a side elevational view of the lead screw of FIG. 62;

FIG. 65 depicts a perspective view of a tensioner of the drive assemblyof FIG. 42;

FIG. 66 depicts a side elevational view of the tensioner of FIG. 65;

FIG. 67 depicts a front elevational view of the tensioner of FIG. 65;

FIG. 68 depicts an exploded perspective view of the tensioner of FIG.65;

FIG. 69 depicts a top plan view of a proximal end of a pair oftranslatable rods of the shaft assembly of FIG. 34;

FIG. 70 depicts another cross-sectional rear view of the drive assemblyof FIG. 42;

FIG. 71 depicts yet another cross-sectional rear view of the driveassembly of FIG. 42;

FIG. 72 depicts yet another cross-sectional rear view of the driveassembly of FIG. 42;

FIG. 73A depicts a partial cross-sectional side view of the driveassembly of FIG. 42, with the lead screw of FIG. 48 in a firstlongitudinal position, with the lead screw of FIG. 59 in a firstlongitudinal position, and with the lead screw of FIG. 62 in a firstlongitudinal position;

FIG. 73B depicts a partial cross-sectional side view of the driveassembly of FIG.

42, with the lead screw of FIG. 48 moved to a second longitudinalposition, with the lead screw of FIG. 59 moved to a second longitudinalposition, and with the lead screw of FIG. 62 moved to a secondlongitudinal position;

FIG. 73C depicts a partial cross-sectional side view of the driveassembly of FIG. 42, with the lead screw of FIG. 48 moved to a thirdlongitudinal position, with the lead screw of FIG. 59 moved to a thirdlongitudinal position, and with the lead screw of FIG. 62 moved to athird longitudinal position;

FIG. 74A depicts a cross-sectional perspective view of the shaftassembly of FIG. 34, with a rod member in a first longitudinal position;

FIG. 74B depicts a cross-sectional perspective view of the shaftassembly of FIG. 34, with the rod member of FIG. 74A moved to a secondlongitudinal position;

FIG. 75A depicts a cross-sectional top view of the shaft assembly ofFIG. 34, with an articulation section of the shaft assembly in astraight configuration;

FIG. 75B depicts a cross-sectional top view of the shaft assembly ofFIG. 34, with the articulation section of FIG. 75B moved to a firstarticulated configuration;

FIG. 75C depicts a cross-sectional top view of the shaft assembly ofFIG. 34, with the articulation section of FIG. 75B moved to a secondarticulated configuration;

FIG. 76 depicts a perspective view of a stiffening assembly that may beused with the ultrasonic surgical instruments of FIGS. 1, 11, and 28;

FIG. 77 depicts a detailed perspective view of a proximal end of atubular member of the stiffening assembly of FIG. 76;

FIG. 78 depicts a detailed perspective view of a tubular guide of thestiffening assembly of FIG. 76;

FIG. 79A depicts a detailed side elevational view of the tubular memberof FIG. 77 coupled with the tubular guide of FIG. 78, with the tubularmember in a first longitudinal position, and with the tubular guide in afirst rotational position;

FIG. 79B depicts a detailed side elevational view of the tubular memberof FIG. 77 coupled with the tubular guide of FIG. 78, with the tubularmember moved to a second longitudinal position by rotation of thetubular guide to a second rotational position;

FIG. 79C depicts a detailed side elevational view of the tubular memberof FIG. 77 coupled with the tubular guide of FIG. 78, with the tubularmember moved to a third longitudinal position by rotation of the tubularguide to a third rotational position;

FIG. 80A depicts a detailed side elevational view of the tubular memberof FIG. 77 in the first longitudinal position relative to anarticulation section;

FIG. 80B depicts a detailed side elevational view of the tubular memberof FIG. 77 moved to the second longitudinal position relative to thearticulation section of FIG. 80A; and

FIG. 80C depicts a detailed side elevational view of the tubular memberof FIG. 77 moved to the third longitudinal position relative to thearticulation section of FIG. 80A.

The drawings are not intended to be limiting in any way, and it iscontemplated that various embodiments of the technology may be carriedout in a variety of other ways, including those not necessarily depictedin the drawings. The accompanying drawings incorporated in and forming apart of the specification illustrate several aspects of the presenttechnology, and together with the description serve to explain theprinciples of the technology; it being understood, however, that thistechnology is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the technology shouldnot be used to limit its scope. Other examples, features, aspects,embodiments, and advantages of the technology will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out thetechnology. As will be realized, the technology described herein iscapable of other different and obvious aspects, all without departingfrom the technology. Accordingly, the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

It is further understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Thefollowing-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

For clarity of disclosure, the terms “proximal” and “distal” are definedherein relative to a human or robotic operator of the surgicalinstrument. The term “proximal” refers the position of an element closerto the human or robotic operator of the surgical instrument and furtheraway from the surgical end effector of the surgical instrument. The term“distal” refers to the position of an element closer to the surgical endeffector of the surgical instrument and further away from the human orrobotic operator of the surgical instrument.

I. Exemplary Ultrasonic Surgical Instrument

FIG. 1 shows an exemplary ultrasonic surgical instrument (10). At leastpart of instrument (10) may be constructed and operable in accordancewith at least some of the teachings of any of the various patents,patent application publications, and patent applications that are citedherein. As described therein and as will be described in greater detailbelow, instrument (10) is operable to cut tissue and seal or weld tissue(e.g., a blood vessel, etc.) substantially simultaneously. It shouldalso be understood that instrument (10) may have various structural andfunctional similarities with the HARMONIC ACE® Ultrasonic Shears, theHARMONIC WAVE® Ultrasonic Shears, the HARMONIC FOCUS® Ultrasonic Shears,and/or the HARMONIC SYNERGY® Ultrasonic Blades. Furthermore, instrument(10) may have various structural and functional similarities with thedevices taught in any of the other references that are cited andincorporated by reference herein.

To the extent that there is some degree of overlap between the teachingsof the references cited herein, the HARMONIC ACE® Ultrasonic Shears, theHARMONIC WAVE® Ultrasonic Shears, the HARMONIC FOCUS® Ultrasonic Shears,and/or the HARMONIC SYNERGY® Ultrasonic Blades, and the followingteachings relating to instrument (10), there is no intent for any of thedescription herein to be presumed as admitted prior art. Severalteachings herein will in fact go beyond the scope of the teachings ofthe references cited herein and the HARMONIC ACE® Ultrasonic Shears, theHARMONIC WAVE® Ultrasonic Shears, the HARMONIC FOCUS® Ultrasonic Shears,and the HARMONIC SYNERGY® Ultrasonic Blades.

Instrument (10) of the present example comprises a handle assembly (20),a shaft assembly (30), and an end effector (40). Handle assembly (20)comprises a body (22) including a pistol grip (24) and a pair of buttons(26). Handle assembly (20) also includes a trigger (28) that ispivotable toward and away from pistol grip (24). It should beunderstood, however, that various other suitable configurations may beused, including but not limited to a scissor grip configuration. Endeffector (40) includes an ultrasonic blade (160) and a pivoting clamparm (44). Clamp arm (44) is coupled with trigger (28) such that clamparm (44) is pivotable toward ultrasonic blade (160) in response topivoting of trigger (28) toward pistol grip (24); and such that clamparm (44) is pivotable away from ultrasonic blade (160) in response topivoting of trigger (28) away from pistol grip (24). Various suitableways in which clamp arm (44) may be coupled with trigger (28) will beapparent to those of ordinary skill in the art in view of the teachingsherein. In some versions, one or more resilient members are used to biasclamp arm (44) and/or trigger (28) to the open position shown in FIG. 1.

An ultrasonic transducer assembly (12) extends proximally from body (22)of handle assembly (20). Transducer assembly (12) is coupled with agenerator (16) via a cable (14), such that transducer assembly (12)receives electrical power from generator (16). Piezoelectric elements intransducer assembly (12) convert that electrical power into ultrasonicvibrations. Generator (16) may include a power source and control modulethat is configured to provide a power profile to transducer assembly(12) that is particularly suited for the generation of ultrasonicvibrations through transducer assembly (12). By way of example only,generator (16) may comprise a GEN 300 sold by Ethicon Endo-Surgery, Inc.of Cincinnati, Ohio. In addition or in the alternative, generator (16)may be constructed in accordance with at least some of the teachings ofU.S. Pub. No. 2011/0087212, entitled “Surgical Generator for Ultrasonicand Electrosurgical Devices,” published Apr. 14, 2011, the disclosure ofwhich is incorporated by reference herein. It should also be understoodthat at least some of the functionality of generator (16) may beintegrated into handle assembly (20), and that handle assembly (20) mayeven include a battery or other on-board power source such that cable(14) is omitted. Still other suitable forms that generator (16) maytake, as well as various features and operabilities that generator (16)may provide, will be apparent to those of ordinary skill in the art inview of the teachings herein.

A. Exemplary End Effector and Acoustic Drivetrain

As best seen in FIGS. 2-4, end effector (40) of the present examplecomprises clamp arm (44) and ultrasonic blade (160). Clamp arm (44)includes a clamp pad (46) that is secured to the underside of clamp arm(44), facing blade (160). Clamp pad (46) may comprisepolytetrafluoroethylene (PTFE) and/or any other suitable material(s).Clamp arm (44) is pivotally secured to a distally projecting tongue (43)of an upper distal shaft element (172), which is fixedly secured withina distal portion of a distal outer sheath (33). Clamp arm (44) isoperable to selectively pivot toward and away from blade (160) toselectively clamp tissue between clamp arm (44) and blade (160). A pairof arms (156) extend transversely from clamp arm (44) and are pivotallysecured to a lower distal shaft element (170), which is slidablydisposed within the distal portion of distal outer sheath (33).

As best seen in FIGS. 7-8, a cable (174) is secured to lower distalshaft element (170). Cable (174) is operable to translate longitudinallyrelative to an articulation section (130) of shaft assembly (30) toselectively pivot clamp arm (44) toward and away from blade (160). Inparticular, cable (174) is coupled with trigger (28) such that cable(174) translates proximally in response to pivoting of trigger (28)toward pistol grip (24), and such that clamp arm (44) thereby pivotstoward blade (160) in response to pivoting of trigger (28) toward pistolgrip (24). In addition, cable (174) translates distally in response topivoting of trigger (28) away from pistol grip (24), such that clamp arm(44) pivots away from blade (160) in response to pivoting of trigger(28) away from pistol grip (24). Clamp arm (44) may be biased toward theopen position, such that (at least in some instances) the operator mayeffectively open clamp arm (44) by releasing a grip on trigger (28).

As shown in FIGS. 7-8, cable (174) is secured to a proximal end of lowerdistal shaft element (170). Lower distal shaft element (170) comprises apair of distal flanges (171, 173) extending from a semi-circular base(168). Flanges (171, 173) each comprise a respective opening (175, 177).Clamp arm (44) is rotatably coupled to lower distal shaft element (170)via a pair of inwardly extending integral pins (41, 45). Pins (41, 45)extend inwardly from arms (156) of clamp arm (44) and are rotatablydisposed within respective openings (175, 177) of lower distal shaftelement (170). As shown in FIGS. 10A-10C, longitudinal translation ofcable (174) causes longitudinal translation of lower distal shaftelement (170) between a proximal position (FIG. 10A) and a distalposition (FIG. 10C). Longitudinal translation of lower distal shaftelement (170) causes rotation of clamp arm (44) between a closedposition (FIG. 10A) and an open position (FIG. 10C).

Blade (160) of the present example is operable to vibrate at ultrasonicfrequencies in order to effectively cut through and seal tissue,particularly when the tissue is being compressed between clamp pad (46)and blade (160). Blade (160) is positioned at the distal end of anacoustic drivetrain. This acoustic drivetrain includes transducerassembly (12) and an acoustic waveguide (180). Acoustic waveguide (180)comprises a flexible portion (166). Transducer assembly (12) includes aset of piezoelectric discs (not shown) located proximal to a horn (notshown) of waveguide (180). The piezoelectric discs are operable toconvert electrical power into ultrasonic vibrations, which are thentransmitted along waveguide (180), including flexible portion (166) ofwaveguide (180) to blade (160) in accordance with known configurationsand techniques. By way of example only, this portion of the acousticdrivetrain may be configured in accordance with various teachings ofvarious references that are cited herein.

As best seen in FIG. 3, flexible portion (166) of waveguide (180)includes a distal flange (136), a proximal flange (138), and a narrowedsection (164) located between flanges (136, 138). In the presentexample, flanges (136, 138) are located at positions corresponding tonodes associated with resonant ultrasonic vibrations communicatedthrough flexible portion (166) of waveguide (180). Narrowed section(164) is configured to allow flexible portion (166) of waveguide (180)to flex without significantly affecting the ability of flexible portion(166) of waveguide (180) to transmit ultrasonic vibrations. By way ofexample only, narrowed section (164) may be configured in accordancewith one or more teachings of U.S. Pub. No. 2014/0005701 and/or U.S.Pub. No. 2014/0114334, the disclosures of which are incorporated byreference herein. It should be understood that waveguide (180) may beconfigured to amplify mechanical vibrations transmitted throughwaveguide (180). Furthermore, waveguide (180) may include featuresoperable to control the gain of the longitudinal vibrations alongwaveguide (180) and/or features to tune waveguide (180) to the resonantfrequency of the system. Various suitable ways in which waveguide (180)may be mechanically and acoustically coupled with transducer assembly(12) will be apparent to those of ordinary skill in the art in view ofthe teachings herein.

In the present example, the distal end of blade (160) is located at aposition corresponding to an anti-node associated with resonantultrasonic vibrations communicated through flexible portion (166) ofwaveguide (180), in order to tune the acoustic assembly to a preferredresonant frequency f_(o) when the acoustic assembly is not loaded bytissue. When transducer assembly (12) is energized, the distal end ofblade (160) is configured to move longitudinally in the range of, forexample, approximately 10 to 500 microns peak-to-peak, and in someinstances in the range of about 20 to about 200 microns at apredetermined vibratory frequency f_(o) of, for example, 55.5 kHz. Whentransducer assembly (12) of the present example is activated, thesemechanical oscillations are transmitted through waveguide (180) to reachblade (160), thereby providing oscillation of blade (160) at theresonant ultrasonic frequency. Thus, when tissue is secured betweenblade (160) and clamp pad (46), the ultrasonic oscillation of blade(160) may simultaneously sever the tissue and denature the proteins inadjacent tissue cells, thereby providing a coagulative effect withrelatively little thermal spread. In some versions, an electricalcurrent may also be provided through blade (160) and clamp arm (44) toalso cauterize the tissue. While some configurations for an acoustictransmission assembly and transducer assembly (12) have been described,still other suitable configurations for an acoustic transmissionassembly and transducer assembly (12) will be apparent to one orordinary skill in the art in view of the teachings herein. Similarly,other suitable configurations for end effector (40) will be apparent tothose of ordinary skill in the art in view of the teachings herein.

B. Exemplary Shaft Assembly and Articulation Section

Shaft assembly (30) of the present example extends distally from handleassembly (20). As shown in FIGS. 2-7, shaft assembly (30) includesdistal outer sheath (33) and a proximal outer sheath (32) that encloseclamp arm (44) drive features and the above-described acoustictransmission features. Shaft assembly (30) further includes anarticulation section (130), which is located at a distal portion ofshaft assembly (30), with end effector (40) being located distal toarticulation section (130). As shown in FIG. 1, a knob (31) is securedto a proximal portion of proximal outer sheath (32). Knob (31) isrotatable relative to body (22), such that shaft assembly (30) isrotatable about the longitudinal axis defined by outer sheath (32),relative to handle assembly (20). Such rotation may provide rotation ofend effector (40), articulation section (130), and shaft assembly (30)unitarily. Of course, rotatable features may simply be omitted ifdesired.

Articulation section (130) is operable to selectively position endeffector (40) at various lateral deflection angles relative to alongitudinal axis defined by outer sheath (32). Articulation section(130) may take a variety of forms. By way of example only, articulationsection (130) may be configured in accordance with one or more teachingsof U.S. Pub. No. 2012/0078247, the disclosure of which is incorporatedby reference herein. As another merely illustrative example,articulation section (130) may be configured in accordance with one ormore teachings of U.S. Pub. No. 2014/0005701 and/or U.S. Pub. No.2014/0114334, the disclosures of which are incorporated by referenceherein. Various other suitable forms that articulation section (130) maytake will be apparent to those of ordinary skill in the art in view ofthe teachings herein. As yet another merely illustrative example,articulation section (130) may be configured in accordance with one ormore teachings of U.S. Pub. No. 2012/0078248, entitled “ArticulationJoint Features for Articulating Surgical Device,” published Mar. 29,2012, the disclosure of which is incorporated by reference herein.

As best seen in FIGS. 2-6B articulation section (130) of this examplecomprises a set of three retention collars (133) and a pair of ribbedbody portions (132, 134), with a pair of articulation bands (140, 142)extending along respective channels (135, 137) defined between interiorsurfaces of retention collars (133) and exterior surfaces of ribbed bodyportions (132, 134). Ribbed body portions (132, 134) are longitudinallypositioned between flanges (136, 138) of flexible portion (166) ofwaveguide (180). In some versions, ribbed body portions (132, 134) snaptogether about flexible portion (166) of waveguide (180). Ribbed bodyportions (132, 134) are configured to flex with flexible portion (166)of waveguide (180) when articulation section (130) bends to achieve anarticulated state.

FIG. 3 shows ribbed body portions (132, 134) in greater detail. In thepresent example, ribbed body portions (132, 134) are formed of aflexible plastic material, though it should be understood that any othersuitable material may be used. Ribbed body portion (132) comprises a setof three ribs (150) that are configured to promote lateral flexing ofribbed body portion (132). Of course, any other suitable number of ribs(150) may be provided. Ribbed body portion (132) also defines a channel(135) that is configured to receive articulation band (140) whileallowing articulation band (140) to slide relative to ribbed bodyportion (132). Similarly, ribbed body portion (134) comprises a set ofthree ribs (152) that are configured to promote lateral flexing ofribbed body portion (134). Of course, any other suitable number of ribs(152) may be provided. Ribbed body portion (134) also defines a channel(137) that is configured to receive articulation band (142) whileallowing articulation band (142) to slide relative to ribbed bodyportion (137).

As best seen in FIG. 5, ribbed body portions (132, 134) are laterallyinterposed between articulation bands (140, 142) and flexible portion(166) of waveguide (180). Ribbed body portions (132, 134) mate with eachother such that they together define an internal passage sized toaccommodate flexible portion (166) of waveguide (180) without contactingwaveguide (180). In addition, when ribbed body portions (132, 134) arecoupled together, a pair of complementary distal notches (131A, 131B)formed in ribbed body portions (132, 134) align to receive a pair ofinwardly projecting resilient tabs (38) of distal outer sheath (33).This engagement between tabs (38) and notches (131A, 131B)longitudinally secures ribbed body portions (132, 134) relative todistal outer sheath (33). Similarly, when ribbed body portions (132,134) are coupled together, a pair of complementary proximal notches(139A, 139B) formed in ribbed body portions (132, 134) align to receivea pair of inwardly projecting resilient tabs (37) of proximal outersheath (32). This engagement between tabs (37) and notches (139A, 139B)longitudinally secures ribbed body portions (132, 134) relative toproximal outer sheath (32). Of course, any other suitable kinds offeatures may be used to couple ribbed body portions (132, 134) withproximal outer sheath (32) and/or distal outer sheath (33).

The distal ends of articulation bands (140, 142) are unitarily securedto upper distal shaft element (172). When articulation bands (140, 142)translate longitudinally in an opposing fashion, this will causearticulation section (130) to bend, thereby laterally deflecting endeffector (40) away from the longitudinal axis of shaft assembly (30)from a straight configuration as shown in FIG. 6A to an articulatedconfiguration as shown in FIG. 6B. In particular, end effector (40) willbe articulated toward the articulation band (140, 142) that is beingpulled proximally. During such articulation, the other articulation band(140, 142) may be pulled distally by upper distal shaft element (172).Alternatively, the other articulation band (140, 142) may be drivendistally by an articulation control. Ribbed body portions (132, 134) andnarrowed section (164) are all sufficiently flexible to accommodate theabove-described articulation of end effector (40). Furthermore, flexibleacoustic waveguide (166) is configured to effectively communicateultrasonic vibrations from waveguide (180) to blade (160) even whenarticulation section (130) is in an articulated state as shown in FIG.6B.

As best seen in FIG. 3, each flange (136, 138) of waveguide (180)includes a respective pair of opposing flats (192, 196). Flats (192,196) are oriented along vertical planes that are parallel to a verticalplane extending through narrowed section (164) of flexible portion(166). Flats (192, 196) are configured to provide clearance forarticulation bands (140, 142). In particular, flats (196) of proximalflange (138) accommodate articulation bands (140, 142) between proximalflange (138) and the inner diameter of proximal outer sheath (32): whileflats (192) of distal flange (136) accommodate articulation bands (140,142) between distal flange (136) and the inner diameter of distal outersheath (33). Of course, flats (192, 196) could be substituted with avariety of features, including but not limited to slots, channels, etc.,with any suitable kind of profile (e.g., square, flat, round, etc.). Inthe present example, flats (192, 196) are formed in a milling process,though it should be understood that any other suitable process(es) maybe used. Various suitable alternative configurations and methods offorming flats (192, 196) will be apparent to those of ordinary skill inthe art in view of the teachings herein. It should also be understoodthat waveguide (180) may include flats formed in accordance with atleast some of the teachings of U.S. Pub. No. 2013/0289592, entitled“Ultrasonic Device for Cutting and Coagulating,” filed Apr. 23, 2013,the disclosure of which is incorporated by reference herein.

In the present example, outer rings (133) are located at longitudinalpositions corresponding to ribs (150, 152), such that three rings (133)are provided for three ribs (150, 152). Articulation band (140) islaterally interposed within channel (135) between rings (133) and ribbedbody portion (132); while articulation band (142) is laterallyinterposed within channel (137) between rings (133) and ribbed bodyportion (134). Rings (133) are configured to keep articulation bands(140, 142) in a parallel relationship, particularly when articulationsection (130) is in a bent configuration (e.g., similar to theconfiguration shown in FIG. 6B). In other words, when articulation band(140) is on the inner diameter of a curved configuration presented by abent articulation section (130), rings (133) may retain articulationband (140) such that articulation band (140) follows a curved path thatcomplements the curved path followed by articulation band (142). Itshould be understood that channels (135, 137) are sized to accommodaterespective articulation bands (140, 142) in such a way that articulationbands (140, 142) may still freely slide through articulation section(130), even with rings (133) being secured to ribbed body portions (150,152). It should also be understood that rings (133) may be secured toribbed body portions (132, 134) in various ways, including but notlimited to interference fitting, adhesives, welding, etc.

When articulation bands (140, 142) are translated longitudinally in anopposing fashion, a moment is created and applied to a distal end ofdistal outer sheath (33) via upper distal shaft element (172). Thiscauses articulation section (130) and narrowed section (164) of flexibleportion (166) of waveguide (180) to articulate, without transferringaxial forces in articulation bands (140, 142) to waveguide (180). Itshould be understood that one articulation band (140, 142) may beactively driven distally while the other articulation band (140, 142) ispassively permitted to retract proximally. As another merelyillustrative example, one articulation band (140, 142) may be activelydriven proximally while the other articulation band (140, 142) ispassively permitted to advance distally. As yet another merelyillustrative example, one articulation band (140, 142) may be activelydriven distally while the other articulation band (140, 142) is activelydriven proximally. Various suitable ways in which articulation bands(140, 142) may be driven will be apparent to those of ordinary skill inthe art in view of the teachings herein.

As best seen in FIG. 9, an articulation control assembly (100) issecured to a proximal portion of outer sheath (32). Articulation controlassembly (100) comprises a housing (110) and a rotatable knob (120).Housing (110) comprises a pair of perpendicularly intersectingcylindrical portions (112, 114). Knob (120) is rotatably disposed withina first hollow cylindrical portion (112) of housing (110) such that knob(120) is operable to rotate within cylindrical portion (112) of housing(110). Shaft assembly (30) is slidably and rotatably disposed within asecond cylindrical portion (114). Shaft assembly (30) comprises a pairof translatable members (161, 162), both of which extend slidably andlongitudinally through the proximal portion of outer sheath (32).Translatable members (161, 162) are longitudinally translatable withinsecond cylindrical portion (114) between a distal position and aproximal position. Translatable members (161, 162) are mechanicallycoupled with respective articulation bands (140, 142) such thatlongitudinal translation of translatable member (161) causeslongitudinal translation of articulation band (140), and such thatlongitudinal translation of translatable member (162) causeslongitudinal translation of articulation band (142).

Knob (120) comprises a pair of pins (122, 124) extending downwardly froma bottom surface of knob (120). Pins (122, 124) extend into secondcylindrical portion (114) of housing (110) and are rotatably andslidably disposed within a respective pair of channels (163, 164) formedin top surfaces of translatable members (161, 162). Channels (163, 164)are positioned on opposite sides of an axis of rotation of knob (120),such that rotation of knob (120) about that axis causes opposinglongitudinal translation of translatable members (161, 162). Forinstance, rotation of knob (120) in a first direction causes distallongitudinal translation of translatable member (161) and articulationband (140), and proximal longitudinal translation of translatable member(162) and articulation band (142); and rotation of knob (120) in asecond direction causes proximal longitudinal translation oftranslatable member (161) and articulation band (140), and distallongitudinal translation of translatable member (162) and articulationband (142). Thus, it should be understood that rotation of rotation knob(120) causes articulation of articulation section (130).

Housing (110) of articulation control assembly (100) comprises a pair ofset screws (111, 113) extending inwardly from an interior surface offirst cylindrical portion (112). With knob (120) rotatably disposedwithin first cylindrical portion (112) of housing (110), set screws(111, 113) are slidably disposed within a pair of arcuate channels (121,123) formed in knob (120). Thus, it should be understood that rotationof knob (120) will be limited by movement of set screws (111, 113)within channels (121, 123). Set screws (111, 113) also retain knob (120)in housing (110), preventing knob (120) from traveling vertically withinfirst cylindrical portion (112) of housing (110).

An interior surface of first cylindrical portion (112) of housing (110)comprises a first angular array of teeth (116) and a second angulararray of teeth (118) formed in an interior surface of first cylindricalportion (112). Rotation knob (120) comprises a pair of outwardlyextending engagement members (126, 128) that are configured to engageteeth (116, 118) of first cylindrical portion (112) in a detentrelationship to thereby selectively lock knob (120) in a particularrotational position. The engagement of engagement members (126, 128)with teeth (116, 118) may be overcome by an operator applying sufficientrotational force to knob (120); but absent such force, the engagementwill suffice to maintain the straight or articulated configuration ofarticulation section (130). It should therefore be understood that theability to selectively lock knob (120) in a particular rotationalposition lock will enable an operator to selectively lock articulationsection (130) in a particular deflected position relative to thelongitudinal axis defined by outer sheath (32).

In some versions of instrument (10), articulation section (130) of shaftassembly (30) is operable to achieve articulation angles up to betweenapproximately 15° and approximately 30°, both relative to thelongitudinal axis of shaft assembly (30) when shaft assembly (30) is ina straight (non-articulated) configuration. Alternatively, articulationsection (130) may be operable to achieve any other suitable articulationangles.

In some versions of instrument (10), narrowed section (164) of waveguide(180) has a thickness between approximately 0.01 inches andapproximately 0.02 inches. Alternatively, narrowed section (164) mayhave any other suitable thickness. Also in some versions, narrowedsection (164) has a length of between approximately 0.4 inches andapproximately 0.65 inches. Alternatively, narrowed section (164) mayhave any other suitable length. It should also be understood that thetransition regions of waveguide (180) leading into and out of narrowedsection (164) may be quarter rounded, tapered, or have any othersuitable configuration.

In some versions of instrument (10), flanges (136, 138) each have alength between approximately 0.1 inches and approximately 0.2 inches.Alternatively, flanges (136, 138) may have any other suitable length. Itshould also be understood that the length of flange (136) may differfrom the length of flange (138). Also in some versions, flanges (136,138) each have a diameter between approximately 0.175 inches andapproximately 0.2 inches. Alternatively, flanges (136, 138) may have anyother suitable outer diameter. It should also be understood that theouter diameter of flange (136) may differ from the outer diameter offlange (138).

While the foregoing exemplary dimensions are provided in the context ofinstrument (10) as described above, it should be understood that thesame dimensions may be used in any of the other examples describedherein. It should also be understood that the foregoing exemplarydimensions are merely optional. Any other suitable dimensions may beused.

II. Exemplary Alternative Articulation Control Configurations withPerpendicular Rotary Knob

When an operator wishes to control articulation of articulation section(130) in instrument (10) as described above, the operator may need touse both hands. In particular, the operator may need to grasp pistolgrip (24) with one hand and grasp knob (120) with the other hand,holding handle assembly (20) stationary via pistol grip (24) while theoperator rotates knob (120). It may be desirable to provide control ofarticulation section (130) without requiring the operator to use bothhands. This may enable the operator to have a free hand to grasp otherinstruments or otherwise use as they see fit. An exemplary alternativeinstrument (200) is described below in which an operator may firmlygrasp instrument (200) and control articulation of an articulationsection (330) using just one single hand. Various suitable ways in whichthe below teachings may be modified will be apparent to those ofordinary skill in the art in view of the teachings herein.

A. Overview

FIGS. 11-27C depict an exemplary electrosurgical instrument (200) thatincludes a handle assembly (220), a shaft assembly (230) extendingdistally from handle assembly (220), and an end effector (240) disposedat a distal end of shaft assembly (230). Handle assembly (220) of thepresent example comprises a body (222) including a pistol grip (224) anda button (226). Handle assembly (220) also includes a trigger (228) thatis pivotable toward and away from pistol grip (224) to selectivelyactuate end effector (240) as described above and as described in one ormore of the references cited herein. It should be understood, however,that various other suitable configurations may be used, including butnot limited to a scissor grip configuration. End effector (240) includesan ultrasonic blade (260) and a pivoting clamp arm (244). Clamp arm(244) is coupled with trigger (228) such that clamp arm (244) ispivotable toward ultrasonic blade (260) in response to pivoting oftrigger (228) toward pistol grip (224); and such that clamp arm (244) ispivotable away from ultrasonic blade (260) in response to pivoting oftrigger (228) away from pistol grip (224). Various suitable ways inwhich clamp arm (244) may be coupled with trigger (228) will be apparentto those of ordinary skill in the art in view of the teachings herein.In some versions, one or more resilient members are used to bias clamparm (244) and/or trigger (228) to the open position shown in FIGS. 11and 12.

An ultrasonic transducer assembly (212) extends proximally from body(222) of handle assembly (220). Transducer assembly (212) is coupledwith a generator (216) via a cable (214), such that transducer assembly(212) receives electrical power from generator (216). Piezoelectricelements in transducer assembly (212) convert that electrical power intoultrasonic vibrations. Generator (216) may include a power source andcontrol module that is configured to provide a power profile totransducer assembly (212) that is particularly suited for the generationof ultrasonic vibrations through transducer assembly (212). By way ofexample only, generator (216) may comprise a GEN 300 sold by EthiconEndo-Surgery, Inc. of Cincinnati, Ohio. In addition or in thealternative, generator (216) may be constructed in accordance with atleast some of the teachings of U.S. Pub. No. 2011/0087212, entitled“Surgical Generator for Ultrasonic and Electrosurgical Devices,”published Apr. 14, 2011, the disclosure of which is incorporated byreference herein. It should also be understood that at least some of thefunctionality of generator (216) may be integrated into handle assembly(220), and that handle assembly (220) may even include a battery orother on-board power source such that cable (214) is omitted. Stillother suitable forms that generator (216) may take, as well as variousfeatures and operabilities that generator (216) may provide, will beapparent to those of ordinary skill in the art in view of the teachingsherein.

An operator may activate button (226) to selectively activate transducerassembly (212) to thereby activate ultrasonic blade (260). In thepresent example, a single button (226) is provided. Button (226) may bedepressed to activate ultrasonic blade (260) at a low power and toactivate ultrasonic blade (260) at a high power. For instance, button(226) may be pressed through a first range of motion to activateultrasonic blade (260) at a low power; and through a second range ofmotion to activate ultrasonic blade (260) at a high power. Of course,any other suitable number of buttons and/or otherwise selectable powerlevels may be provided. For instance, a foot pedal may be provided toselectively activate transducer assembly (212). Button (226) of thepresent example is positioned such that an operator may readily fullyoperate instrument (200) with a single hand. For instance, the operatormay position their thumb about pistol grip (224), position their middle,ring, and/or little finger about trigger (228), and manipulate button(226) using their index finger. Alternatively, any other suitabletechniques may be used to grip and operate instrument (200); and button(226) may be located at any other suitable positions.

In some versions, button (226) also serves as a mechanical lockoutagainst trigger (224), such that trigger (224) cannot be fully actuatedunless button (226) is being pressed simultaneously. Examples of howsuch a lockout may be provided are disclosed in one or more of thereferences cited herein. It should be understood that pistol grip (222),trigger (224), and button (226) may be modified, substituted,supplemented, etc. in any suitable way, and that the descriptions ofsuch components herein are merely illustrative.

B. Exemplary End Effector and Acoustic Drivetrain

As best seen in FIGS. 11 and 12, end effector (240) of the presentexample comprises clamp arm (244) and ultrasonic blade (260). Clamp arm(244) includes a clamp pad (246) that is secured to the underside ofclamp arm (244), facing ultrasonic blade (260). Clamp pad (246) maycomprise PTFE and/or any other suitable material(s). Clamp arm (244) isoperable to selectively pivot toward and away from ultrasonic blade(260) to selectively clamp tissue between clamp arm (244) and blade(260).

As with clamp arm (44) discussed above, clamp arm (244) of the presentexample is pivotally secured to a cable (274). Cable (274) is slidablydisposed within an outer sheath (232) of shaft assembly (230) as shownin FIGS. 15-16. Cable (274) is operable to translate longitudinallyrelative to an articulation section (330) of shaft assembly (230) toselectively pivot clamp arm (244) toward and away from blade (260). Inparticular, cable (274) is coupled with trigger (228) such that cable(274) translates proximally in response to pivoting of trigger (228)toward pistol grip (224), and such that clamp arm (244) thereby pivotstoward blade (260) in response to pivoting of trigger (228) towardpistol grip (224). In addition, cable (274) translates distally inresponse to pivoting of trigger (228) away from pistol grip (224), suchthat clamp arm (244) pivots away from blade (260) in response topivoting of trigger (228) away from pistol grip (224). Clamp arm (244)may be biased toward the open position, such that (at least in someinstances) the operator may effectively open clamp arm (244) byreleasing a grip on trigger (228). It should be understood that clamparm (244) is merely optional, such that clamp arm (244) may be omittedif desired.

Blade (260) of the present example is operable to vibrate at ultrasonicfrequencies in order to effectively cut through and seal tissue,particularly when the tissue is being compressed between clamp pad (246)and blade (260). Blade (260) is positioned at the distal end of anacoustic drivetrain. This acoustic drivetrain includes transducerassembly (212) and an acoustic waveguide (280). Acoustic waveguide (280)comprises a flexible portion (266). Transducer assembly (212) includes aset of piezoelectric discs (not shown) located proximal to a horn (notshown) of waveguide (280). The piezoelectric discs are operable toconvert electrical power into ultrasonic vibrations, which are thentransmitted along waveguide (280), including flexible portion (266) ofwaveguide (280) to blade (260) in accordance with known configurationsand techniques. By way of example only, this portion of the acousticdrivetrain may be configured in accordance with various teachings ofvarious references that are cited herein.

As with flexible portion (166) of waveguide (180) discussed above,flexible portion (266) of waveguide (280) includes a narrowed section(264). Narrowed section (264) is configured to allow flexible portion(266) of waveguide (280) to flex without significantly affecting theability of flexible portion (266) of waveguide (280) to transmitultrasonic vibrations. By way of example only, narrowed section (264)may be configured in accordance with one or more teachings of U.S. Pub.No. 2014/0005701 and/or U.S. Pub. No. 2014/0114334, the disclosures ofwhich are incorporated by reference herein. It should be understood thatwaveguide (280) may be configured to amplify mechanical vibrationstransmitted through waveguide (280). Furthermore, waveguide (280) mayinclude features operable to control the gain of the longitudinalvibrations along waveguide (280) and/or features to tune waveguide (280)to the resonant frequency of the system. Various suitable ways in whichwaveguide (280) may be mechanically and acoustically coupled withtransducer assembly (212) will be apparent to those of ordinary skill inthe art in view of the teachings herein.

In the present example, the distal end of blade (260) is located at aposition corresponding to an anti-node associated with resonantultrasonic vibrations communicated through flexible portion (266) ofwaveguide (280), in order to tune the acoustic assembly to a preferredresonant frequency f_(o) when the acoustic assembly is not loaded bytissue. When transducer assembly (212) is energized, the distal end ofblade (260) is configured to move longitudinally in the range of, forexample, approximately 10 to 500 microns peak-to-peak, and in someinstances in the range of about 20 to about 200 microns at apredetermined vibratory frequency f_(o) of, for example, 55.5 kHz. Whentransducer assembly (212) of the present example is activated, thesemechanical oscillations are transmitted through waveguide (280) to reachblade (260), thereby providing oscillation of blade (260) at theresonant ultrasonic frequency. Thus, when tissue is secured betweenblade (260) and clamp pad (246), the ultrasonic oscillation of blade(260) may simultaneously sever the tissue and denature the proteins inadjacent tissue cells, thereby providing a coagulative effect withrelatively little thermal spread. In some versions, an electricalcurrent may also be provided through blade (260) and clamp arm (244) toalso cauterize the tissue. While some configurations for an acoustictransmission assembly and transducer assembly (212) have been described,still other suitable configurations for an acoustic transmissionassembly and transducer assembly (212) will be apparent to one orordinary skill in the art in view of the teachings herein. Similarly,other suitable configurations for end effector (240) will be apparent tothose of ordinary skill in the art in view of the teachings herein.

C. Exemplary Shaft Assembly and Articulation Section

Shaft assembly (230) of the present example extends distally from handleassembly (220). As best seen in FIGS. 11 and 12, shaft assembly (230)includes distal outer sheath (233) and a proximal outer sheath (232)that enclose the drive features of clamp arm (244) and theabove-described acoustic transmission features. Shaft assembly (230)further includes an articulation section (330), which is located at adistal portion of shaft assembly (230), with end effector (240) beinglocated distal to articulation section (330).

Articulation section (330) of the present example is configured andoperable substantially similar to articulation section (130) discussedabove except for the differences discussed below. In particular,articulation section (330) is operable to selectively position endeffector (240) at various lateral deflection angles relative to alongitudinal axis defined by outer sheath (232). Articulation section(330) may take a variety of forms. By way of example only, articulationsection (330) may be configured in accordance with one or more teachingsof U.S. Pub. No. 2012/0078247, the disclosure of which is incorporatedby reference herein. As another merely illustrative example,articulation section (330) may be configured in accordance with one ormore teachings of U.S. Pub. No. 2014/0005701 and/or U.S. Pub. No.2014/0114334, the disclosures of which are incorporated by referenceherein. Various other suitable forms that articulation section (330) maytake will be apparent to those of ordinary skill in the art in view ofthe teachings herein.

As shown in FIGS. 15-16, shaft assembly (230) further comprises a pairof articulation bands (340, 342) and a pair of translatable rods (440,442). Articulation bands (340, 342) are configured to operatesubstantially similar to articulation bands (140, 142) discussed above,except for any differences discussed below. For instance, whenarticulation bands (340, 342) translate longitudinally in an opposingfashion, this will cause articulation section (330) to bend, therebylaterally deflecting end effector (240) away from the longitudinal axisof shaft assembly (230) from a straight configuration as shown in FIG.27A to an articulated configuration as shown in FIGS. 27B and 27C. Inparticular, end effector (240) will be articulated toward thearticulation band (340, 342) that is being pulled proximally. Duringsuch articulation, the other articulation band (340, 342) may be pulleddistally. Alternatively, the other articulation band (340, 342) may bedriven distally by articulation control assembly (400), which isdescribed in greater detail below. Flexible acoustic waveguide (266) isconfigured to effectively communicate ultrasonic vibrations fromwaveguide (280) to blade (260) even when articulation section (330) isin an articulated state as shown in FIGS. 27B and 27C.

Translatable members (440, 442) are slidably disposed within theproximal portion of outer sheath (232). Translatable members (440, 442)extend longitudinally through the proximal portion of outer sheath (232)along opposite sides of outer sheath (232) and adjacent an interiorsurface of outer sheath (232). As shown in FIG. 16, an elongate recess(444) is formed in an exterior surface of a distal portion of eachtranslatable member (440, 442). Elongate recesses (444) are configuredto receive a proximal portion of each articulation band (340, 342). Eachtranslatable member (440, 442) further includes a pin (443) projectingoutwardly from an interior surface of each elongate recess (444). Anopening (341) formed in a proximal end of each articulation band (340,342) is configured to receive a respective pin (443) of translatablemembers (440, 442). Pins (443) and openings (341, 343) thus function tomechanically couple translatable members (440, 442) with articulationbands (340, 342) such that longitudinal translation of translatablemember (440) causes concurrent longitudinal translation of articulationband (340), and such that longitudinal translation of translatablemember (442) causes concurrent longitudinal translation of articulationband (342).

When translatable members (440, 442) and articulation bands (340, 342)are translated longitudinally in an opposing fashion, a moment iscreated and applied to a distal end of distal outer sheath (233) in thesame manner as described above with respect to articulation section(130). This causes articulation section (330) and narrowed section (264)of flexible portion (266) of waveguide (280) to articulate, withouttransferring axial forces in articulation bands (340, 342) to waveguide(280) as described above. It should be understood that one articulationband (340, 342) may be actively driven distally while the otherarticulation band (340, 342) is passively permitted to retractproximally. As another merely illustrative example, one articulationband (340, 342) may be actively driven proximally while the otherarticulation band (340, 342) is passively permitted to advance distally.As yet another merely illustrative example, one articulation band (340,342) may be actively driven distally while the other articulation band(340, 342) is actively driven proximally. Various suitable ways in whicharticulation bands (340, 342) may be driven will be apparent to those ofordinary skill in the art in view of the teachings herein.

As shown in FIGS. 11-14, a rotation knob (231) is secured to a proximalportion of proximal outer sheath (232). Rotation knob (231) is rotatablerelative to body (222), such that shaft assembly (230) is rotatableabout the longitudinal axis defined by outer sheath (232), relative tohandle assembly (220). Such rotation may provide rotation of endeffector (240), articulation section (330), and shaft assembly (230)unitarily. Of course, rotatable features may simply be omitted ifdesired.

D. Exemplary Articulation Control Assembly

FIGS. 17-27C show the components and operation of an articulationcontrol assembly (400) that is configured to provide control forarticulation of articulation section (330). Articulation controlassembly (400) comprises an articulation control knob (402) and a bevelgear (404). Articulation control knob (402) is rotatably disposed withina distal portion of body (222) of handle assembly (220). As best seen inFIG. 14, articulation control knob (402) is oriented within body (222)and relative to shaft assembly (230) such that articulation control knob(402) is configured to rotate about an axis that is perpendicular to thelongitudinal axis defined by shaft assembly (230). A portion ofarticulation control knob (402) is exposed relative to body (222) suchthat an operator may engage articulation control knob (402) to therebyrotate articulation control knob (402). For example, while gripping body(222) via pistol grip (224), an operator may use his or her index fingeror thumb to rotate articulation control knob (402). It should thereforebe understood that the operator may rotate knob (402) using the samehand that grasps pistol grip (224). As will be described in more detailbelow, rotation of articulation control knob (402) is configured tocause articulation of articulation section (330). Since the operator mayuse the same hand to rotate knob (402) and simultaneously grasp pistolgrip (224), articulation control assembly (400) of this example providesfull control of instrument (200)—including pivoting of trigger (228),actuation of button (226), and actuation of knob (402)—with just onesingle hand, such the operator's other hand may be completely freeduring the entire period when any and all functionality of instrument(200) is being used.

Articulation control assembly (400) further includes a structural frame(370) secured within a proximal portion of an interior of body (222) ofhandle assembly (220) such that structural frame (370) is configured toremain stationary within body (222). As best seen in FIGS. 17 and 18,bevel gear (404) is rotatably disposed about a cylindrical projection(372) of structural frame (370). As best seen in FIG. 14, bevel gear(404) is mechanically coupled with articulation control knob (402) via aslot (406) formed in bevel gear (404) and a mating key (408) projectingfrom a top surface of articulation control knob (402) such that rotationof articulation control knob (402) causes concurrent rotation of bevelgear (404) about cylindrical projection (372) of structural frame (370).Bevel gear (404) includes a plurality of teeth (410) and a detentfeature (412). As will be described in more detail below, teeth (410) ofbevel gear (404) mesh with teeth (439) of a bevel gear (438) of a driveassembly (420), such that rotation of bevel gear (404) drivesarticulation of articulation section (330).

Detent feature (412) is configured to selectively engage acomplementary, resiliently biased detent feature (223) of handleassembly (220) as best seen in FIG. 14. Detent feature (412) ispositioned to engage detent feature (223) when control knob (402) isrotated to a “neutral” position associated with articulation section(330) being in a straight configuration. It should therefore beunderstood that detent features (224, 412) may cooperate to provide theoperator with tactile feedback via control knob (402) to indicate thatarticulation section (330) is in the straight configuration. Detentfeatures (224, 412) may also cooperate to provide some degree ofmechanical resistance to rotation of knob (402) from the neutralposition, thereby resisting inadvertent articulation of articulationsection (330) that might otherwise result from incidental contactbetween knob (402) and the operator's hand, etc.

In addition to or in lieu of including detent features (224, 412), knob(402) may include a visual indicator that is associated witharticulation section (330) being in a substantially straightconfiguration. Such a visual indicator may align with a correspondingvisual indicator on body (222) of handle assembly (220). Thus, when anoperator has rotated knob (402) to make articulation section (330)approach a substantially straight configuration, the operator mayobserve such indicators to confirm whether articulation section (330)has in fact reached a substantially straight configuration. By way ofexample only, this may be done right before instrument (200) iswithdrawn from a trocar to reduce the likelihood of articulation section(330) snagging on a distal edge of the trocar. Of course, suchindicators are merely optional.

As best seen in FIG. 17, articulation control assembly (400) furthercomprises a drive assembly (420). Drive assembly (420) is secured to aproximal portion of proximal outer sheath (232). Drive assembly (420) isfurther rotatably disposed within rotation knob (231) such that rotationknob (231) is configured to rotate independently about drive assembly(420) to thereby cause rotation of shaft assembly (230) without causingrotation of drive assembly (420).

Drive assembly (420) comprises a housing (430), a pair of lead screws(450, 460), and a cylindrical guide (470). Housing (430) comprises apair of mating semi-cylindrical shrouding halves (432, 434) and a bevelgear (438). When coupled to one another, shrouding halves (432, 434)form a cylindrical shroud (431). A proximal end of shroud (431) iscoupled with and closed-off by bevel gear (438). Shroud (431), togetherwith bevel gear (438), form housing (430) which substantiallyencompasses the internal components of drive assembly (420) as will bedescribed in more detail below.

Bevel gear (438) includes a plurality of teeth (439). Teeth (439) ofbevel gear (438) are configured to engage teeth (410) of bevel gear(404) such that rotation of bevel gear (404) causes concurrent rotationof bevel gear (438). It should therefore be understood that rotation ofarticulation control knob (402) is configured to cause concurrentrotation of housing (430) via bevel gears (404, 438).

As best seen in FIG. 18, shrouding halves (432, 434) each includeproximal internal threading (433A) formed in an interior surface of eachshrouding half (432, 434). Internal threadings (433A) are configured toalign with one another when shrouding halves (432, 434) are coupledtogether to form a continuous internal proximal threading (433) withinhousing (430). Shrouding halves (432, 434) each further include distalinternal threading (435A) formed in an interior surface of eachshrouding half (432, 434). Internal threadings (435A) are configured toalign with one another when shrouding halves (432, 434) are coupledtogether to form a continuous internal distal threading (435) withinhousing (430). Threadings (433, 435) have opposing pitch angles ororientations in this example, such that the pitch orientation ofthreading (433) is opposite the pitch orientation of threading (435).

As shown in FIGS. 20-21, a first lead screw (450) includes exteriorthreading (452) that is configured to engage with threading (433) ofhousing (430). As shown in FIGS. 22-23 a second lead screw (460)includes exterior threading (462) that is configured to engage withthreading (435) of housing (430). The pitch angle of threading (452)complements the pitch angle of threading (433); while the pitch angle ofthreading (462) complements the pitch angle of threading (435). Asdescribed in greater detail below, both lead screws (450, 460) arepermitted to translate within drive assembly (420) but are preventedfrom rotating within drive assembly (420). It should therefore beunderstood that, due to the opposing pitch angles, rotation of housing(430) in a first direction will drive lead screw (450) distally whilesimultaneously driving lead screw (460) proximally; and rotation ofhousing (430) in a second direction will drive lead screw (450)proximally while simultaneously driving lead screw (460) distally.

As best seen in FIGS. 21 and 23, a through-bore (454, 464) formed ineach lead screw (450, 460) includes a pair of recesses (456, 466) formedin radially opposing sides of an interior surface of through-bores (454,464). Cylindrical guide (470) is positioned within housing (430) aboutthe proximal portion of outer sheath (232). As shown in FIGS. 24A and24B, cylindrical guide (470) is secured to a distal end of structuralframe (370) via a pair of semi-circular recesses (374) formed in thedistal end of structural frame (370) and a pair of semi-circularprojections (476) extending proximally from cylindrical guide (470).Thus, with structural frame (370) secured within the proximal portion ofthe interior of body (222) of handle assembly (220) as described above,cylindrical guide (470) is configured to remain stationary withinhousing (430). A bearing member (436) is coupled to a distal end ofcylindrical guide (470) via a pair of semi-circular recesses (437)formed in bearing member (436) and a pair of semi-circular projections(478) extending distally from cylindrical guide (470). A circular flange(441) of bearing member (436) is rotatable disposed within a pair ofmating circular recesses (451A) formed in a distal end of shroud halves(432, 434) such that housing (430) is operable to rotate about bearingmember (436).

As best seen in FIGS. 24A and 24B, cylindrical guide (470) comprises aproximal pair of longitudinal tracks (472) and a distal pair oflongitudinal tracks (474) formed in opposing sides of a sidewall ofcylindrical guide (470). As shown in FIG. 25, proximal longitudinaltracks (472) are configured to be received within recesses (456) offirst lead screw (450) such that first lead screw (450) is slidablydisposed along proximal longitudinal tracks (472). As shown in FIG. 26,distal longitudinal tracks (474) are configured to be received withinrecesses (466) of second lead screw (460) such that second lead screw(460) is slidably disposed along distal longitudinal tracks (474). Thus,lead screws (450, 460) are operable to translate within housing (430)but are prevented from rotating within housing (430).

As shown in FIG. 25, first lead screw (450) is secured to a proximal endof translatable member (440) via a coupler (458). An exterior surface ofcoupler (458) is secured to an interior surface of through-bore (454) offirst lead screw (450). A key (459) of coupler (458) is positionedwithin a mating slot (447) formed in the proximal end of translatablemember (440) such that longitudinal translation of first lead screw(450) causes concurrent translation of translatable member (440) andarticulation band (340). Thus, in the present version, first lead screw(450) is operable to both push articulation band (340) distally and pullarticulation band (340) proximally, depending on which direction housing(430) is rotated. Other suitable relationships will be apparent to thoseof ordinary skill in the art in view of the teachings herein.

As shown in FIG. 26, second lead screw (460) is secured to a proximalend of translatable member (442) via a coupler (468). An exteriorsurface of coupler (468) is secured to an interior surface ofthrough-bore (464) of second lead screw (460). A key (469) of coupler(468) is positioned within a mating slot (449) formed in the proximalend of translatable member (442) such that longitudinal translation ofsecond lead screw (460) causes concurrent translation of translatablemember (422) and articulation band (342). Thus, in the present version,second lead screw (460) is operable to both push articulation band (342)distally and pull articulation band (342) proximally, depending on whichdirection housing (430) is rotated. Other suitable relationships will beapparent to those of ordinary skill in the art in view of the teachingsherein.

FIGS. 27A-27C show several of the above described components interactingto bend articulation section (330) to articulate end effector (240) inresponse to rotation of knob (402) relative to handle assembly (220). Itshould be understood that in FIGS. 27A-27C depicts a side elevationalview of handle assembly (220) and a top plan view of shaft assembly(230), including articulation section (330). In FIG. 27A, articulationsection (330) is in a substantially straight configuration. Then,housing (430) is rotated by rotation of articulation knob (402). Inparticular, rotation of articulation knob (402) is communicated tohousing (430) via meshing bevel gears (410, 438). The resulting rotationof housing (430) which causes first lead screw (450) to translateproximally and second lead screw (460) to advance distally. Thisproximal translation of first lead screw (450) pulls articulation band(340) proximally via translatable member (440), which causesarticulation section (330) to start bending as shown in FIG. 27B. Thisbending of articulation section (330) pulls articulation band (342)distally. The distal advancement of second lead screw (460) in responseto rotation of housing (430) enables articulation band (342) andtranslatable member (442) to advance distally. In some other versions,the distal advancement of second lead screw (460) actively drivestranslatable member (442) and articulation band (342) distally. As theoperator continues rotating housing (430) by rotating articulation knob(402), the above described interactions continue in the same fashion,resulting in further bending of articulation section (330) as shown inFIG. 27C.

It should be understood that, after reaching the articulation state inFIG. 27C by rotating knob (402) in a first direction, rotation of knob(402) in a second (opposite) direction will cause articulation section(330) to return to the straight configuration shown in FIG. 27A. Asnoted above, detent features (224, 412) may cooperate to provide tactilefeedback via knob (402) to indicate that articulation section (330) hasreached the straight configuration. Still further rotation of knob (402)in that second direction will eventually result in articulation section(330) deflecting in a direction opposite to that shown in FIGS. 27B-27C.

The angles of threading (433, 435, 452, 462) are configured such thatarticulation section (330) will be effectively locked in any givenarticulated position, such that transverse loads on end effector (240)will generally not bend articulation section (330), due to frictionbetween threading (433, 435, 452, 462). In other words, articulationsection (330) will only change its configuration when housing (430) isrotated via knob (402). While the angles of threading may substantiallyprevent bending of articulation section (330) in response to transverseloads on end effector (240), the angles may still provide ready rotationof housing (430) to translate lead screws (450, 460). By way of exampleonly, the angles of threading (433, 435, 452, 462) may be approximately+/−2 degrees or approximately +/−3 degrees. Other suitable angles willbe apparent to those of ordinary skill in the art in view of theteachings herein. It should also be understood that threading (433, 435,452, 462) may have a square or rectangular cross-section or any othersuitable configuration.

In some instances, manufacturing inconsistencies may result inarticulation bands (340, 342) and/or translatable members (440, 442)having slightly different lengths. In addition or in the alternative,there may be inherent manufacturing related inconsistencies in theinitial positioning of lead screws (450, 460) relative to housing (430)and/or other inconsistencies that might result in undesirablepositioning/relationships of articulation bands (340, 342) and/ortranslatable members (440, 442). Such inconsistencies may result in lostmotion or slop in the operation of the articulation features ofinstrument (200). To address such issues, tensioner gears (not shown)may be incorporated into drive assembly (420) to adjust the longitudinalposition of translatable members (440, 442) relative to lead screws(450, 460). Lead screws (450, 460) may remain substantially stationaryduring such adjustments. Articulation section (330) may remainsubstantially straight during such adjustments and may even be heldsubstantially straight during such adjustments.

In addition to or in lieu of the foregoing, drive assembly (420) may beconfigured and operable in accordance with at least some of theteachings of U.S. Pub. No. 2013/0023868, entitled “Surgical Instrumentwith Contained Dual Helix Actuator Assembly,” published Jan. 24, 2013,the disclosure of which is incorporated by reference herein; in U.S.Pub. No. 2012/0078243, entitled “Control Features for ArticulatingSurgical Device,” published Mar. 29, 2012, the disclosure of which isincorporated by reference herein; and in U.S. Pub. No. 2012/0078244,entitled “Control Features for Articulating Surgical Device,” publishedMar. 29, 2012, the disclosure of which is incorporated by referenceherein.

III. Exemplary Motorized Articulation Control Assembly and RigidizingMember

In some versions of instruments (10, 200) it may be desirable to providemotorized control of articulation section (130, 330). This may furtherpromote single-handed use of the instrument, such that two hands are notrequired in order to control articulation section (130, 300).

It may also be desirable to provide features that are configured toselectively provide rigidity to articulation sections (130, 330). Forinstance, because of various factors such as manufacturing tolerances,design limitations, material limitations, and/or other factors, someversions of articulation sections (130, 330) may be susceptible to some“play” or other small movement of the articulation section despite beingrelatively fixed in a given position, such that articulation sections(130, 330) are not entirely rigid. It may be desirable to reduce oreliminate such play in articulation sections (130, 330), particularlywhen articulation sections (130, 330) are in a straight, non-articulatedconfiguration. Features may thus be provided to selectively rigidizearticulation sections (130, 330). Various examples of features that areconfigured to selectively provide rigidity to articulation sections(130, 330) and/or to limit or prevent inadvertent deflection of endeffectors (40, 240) will be described in greater detail below. Otherexamples will be apparent to those of ordinary skill in the artaccording to the teachings herein. It should be understood that theexamples of shaft assemblies and/or articulation sections describedbelow may function substantially similar to shaft assemblies (30, 230)discussed above.

It should also be understood that articulation sections (130, 330) maystill be at least somewhat rigid before being modified to include therigidizing features described below, such that the rigidizing featuresdescribed below actually just increase the rigidity of articulationsections (130, 330) rather than introducing rigidity to otherwisenon-rigid articulation sections (130, 330). For instance, articulationsections (130, 330) in the absence of features as described below may berigid enough to substantially maintain a straight or articulatedconfiguration; yet may still provide “play” of about 1 mm or a fractionthereof such that the already existing rigidity of articulation sections(130, 330) may be increased. Thus, terms such as “provide rigidity,”“providing rigidity,” “rigidize,” and “rigidizing,” etc. shall beunderstood to include just increasing rigidity that is already presentin some degree. The terms ““provide rigidity,” “providing rigidity,”“rigidize,” and “rigidizing,” etc. should not be read as necessarilyrequiring articulation sections (130, 330) to completely lack rigiditybefore the rigidity is “provided.”

A. Overview

FIGS. 28-30 show an exemplary ultrasonic surgical instrument (500) thatis configured to be used in minimally invasive surgical procedures(e.g., via a trocar or other small diameter access port, etc.). As willbe described in greater detail below, instrument (500) is operable tocut tissue and seal or weld tissue (e.g., a blood vessel, etc.)substantially simultaneously. Instrument (500) of this example comprisesa disposable assembly (501) and a reusable assembly (502). The distalportion of reusable assembly (502) is configured to removably receivethe proximal portion of disposable assembly (501), as seen in FIGS.29-30, to form instrument (500). By way of example only, instrument(500) may be configured and operable in accordance with at least some ofthe teachings of U.S. Pat. App. No. 14/623,812, entitled “UltrasonicSurgical Instrument with Removable Handle Assembly,” filed Feb. 17,2015, the disclosure of which is incorporated by reference herein.

In an exemplary use, assemblies (501, 502) are coupled together to forminstrument (500) before a surgical procedure, the assembled instrument(500) is used to perform the surgical procedure, and then assemblies(501, 502) are decoupled from each other for further processing. In someinstances, after the surgical procedure is complete, disposable assembly(501) is immediately disposed of while reusable assembly (502) issterilized and otherwise processed for re-use. By way of example only,reusable assembly (502) may be sterilized in a conventional relativelylow temperature, relatively low pressure, hydrogen peroxidesterilization process. Alternatively, reusable assembly (502) may besterilized using any other suitable systems and techniques (e.g.,autoclave, etc.). In some versions, reusable assembly (502) may besterilized and reused approximately 100 times. Alternatively, reusableassembly (502) may be subject to any other suitable life cycle. Forinstance, reusable assembly (502) may be disposed of after a single use,if desired. While disposable assembly (501) is referred to herein asbeing “disposable,” it should be understood that, in some instances,disposable assembly (501) may also be sterilized and otherwise processedfor re-use. By way of example only, disposable assembly (501) may besterilized and reused approximately 2-30 times, using any suitablesystems and techniques. Alternatively, disposable assembly (501) may besubject to any other suitable life cycle.

In some versions, disposable assembly (501) and/or reusable assembly(502) includes one or more features that are operable to track usage ofthe corresponding assembly (501, 502), and selectively restrictoperability of the corresponding assembly (501, 502) based on use. Forinstance, disposable assembly (501) and/or reusable assembly (502) mayinclude one or more counting sensors and a control logic (e.g.,microprocessor, etc.) that is in communication with the countingsensor(s). The counting sensor(s) may be able to detect the number oftimes the ultrasonic transducer of instrument (500) is activated, thenumber of surgical procedures the corresponding assembly (501, 502) isused in, the number of trigger closures, and/or any other suitableconditions associated with use. The control logic may track data fromthe counting sensor(s) and compare the data to one or more thresholdvalues. When the control logic determines that one or more thresholdvalues have been exceeded, the control logic may execute a controlalgorithm to disable operability of one or more components in thecorresponding assembly (501, 502). In instances where the control logicstores two or more threshold values (e.g., a first threshold for numberof activations and a second threshold for number of surgical procedures,etc.), the control logic may disable operability of one or morecomponents in the corresponding assembly (501, 502) the first time oneof those thresholds is exceeded, or on some other basis.

In versions where a control logic is operable to disable instrument(500) based on the amount of use, the control logic may also determinewhether instrument (500) is currently being used in a surgicalprocedure, and refrain from disabling instrument (500) until thatparticular surgical procedure is complete. In other words, the controllogic may allow the operator to complete the current surgical procedurebut prevent instrument (500) from being used in a subsequent surgicalprocedure. Various suitable forms that counters or other sensors maytake will be apparent to those of ordinary skill in the art in view ofthe teachings herein. Various suitable forms that a control logic maytake will also be apparent to those of ordinary skill in the art in viewof the teachings herein. Similarly, various suitable control algorithmsthat may be used to restrict usage of instrument (500) will be apparentto those of ordinary skill in the art in view of the teachings herein.Of course, some versions of instrument (500) may simply omit featuresthat track and/or restrict the amount of usage of instrument (500).

As shown in FIGS. 31-75C, disposable assembly (501) of the presentexample comprises a body portion (520), a shaft assembly (530) extendingdistally from body portion (520), and an end effector (540) disposed ata distal end of shaft assembly (530). Body portion (520) of the presentexample comprises a housing (522) which includes a button (526). Button(526) is operable just like button (226) described above. Body portion(520) also includes a trigger (528) that is pivotable toward and awayfrom a pistol grip (524) of reusable assembly (502) to selectivelyactuate end effector (540) as described above and as described in one ormore of the references cited herein. It should be understood, however,that various other suitable configurations may be used, including butnot limited to a scissor grip configuration. End effector (540) includesan ultrasonic blade (560) and a pivoting clamp arm (544). Clamp arm(544) is coupled with trigger (528) such that clamp arm (544) ispivotable toward ultrasonic blade (560) in response to pivoting oftrigger (528) toward pistol grip (524); and such that clamp arm (544) ispivotable away from ultrasonic blade (560) in response to pivoting oftrigger (528) away from pistol grip (524). Various suitable ways inwhich clamp arm (544) may be coupled with trigger (528) will be apparentto those of ordinary skill in the art in view of the teachings herein.In some versions, one or more resilient members are used to bias clamparm (544) and/or trigger (528) to the open position shown in FIGS.28-30. It should also be understood that clamp arm (544) may be omittedif desired.

B. Exemplary End Effector and Acoustic Drivetrain

As discussed above, end effector (540) of the present example comprisesclamp arm (544) and ultrasonic blade (560). Clamp arm (544) includes aclamp pad (546) that is secured to the underside of clamp arm (544),facing ultrasonic blade (560). Clamp pad (546) may comprise PTFE and/orany other suitable material(s). Clamp arm (544) is operable toselectively pivot toward and away from ultrasonic blade (560) toselectively clamp tissue between clamp arm (544) and blade (560).

As with clamp arms (44, 244) discussed above, clamp arm (544) of thepresent example is pivotally secured to a cable (574). Cable (574) isslidably disposed within an outer sheath (532) of shaft assembly (530)as shown in FIG. 34. Cable (574) is operable to translate longitudinallyrelative to an articulation section (630) of shaft assembly (530) toselectively pivot clamp arm (544) toward and away from blade (560). Inparticular, cable (574) is coupled with trigger (528) such that cable(574) translates proximally in response to pivoting of trigger (528)toward pistol grip (524), and such that clamp arm (544) thereby pivotstoward blade (560) in response to pivoting of trigger (528) towardpistol grip (524). In addition, cable (574) translates distally inresponse to pivoting of trigger (528) away from pistol grip (524), suchthat clamp arm (544) pivots away from blade (560) in response topivoting of trigger (528) away from pistol grip (524). Clamp arm (544)may be biased toward the open position, such that (at least in someinstances) the operator may effectively open clamp arm (544) byreleasing a grip on trigger (528).

Blade (560) of the present example is operable to vibrate at ultrasonicfrequencies in order to effectively cut through and seal tissue,particularly when the tissue is being compressed between clamp pad (546)and blade (560). Blade (560) is positioned at the distal end of anacoustic drivetrain. Acoustic waveguide (580) comprises a flexibleportion (266). As with flexible portions (166, 266) of waveguides (180,280) discussed above, flexible portion (566) of waveguide (580) includesa narrowed section (564). Narrowed section (564) is configured to allowflexible portion (566) of waveguide (580) to flex without significantlyaffecting the ability of flexible portion (566) of waveguide (580) totransmit ultrasonic vibrations. By way of example only, narrowed section(564) may be configured in accordance with one or more teachings of U.S.Pub. No. 2014/0005701 and/or U.S. Pub. No. 2014/0114334, the disclosuresof which are incorporated by reference herein. It should be understoodthat waveguide (580) may be configured to amplify mechanical vibrationstransmitted through waveguide (580). Furthermore, waveguide (580) mayinclude features operable to control the gain of the longitudinalvibrations along waveguide (580) and/or features to tune waveguide (580)to the resonant frequency of the system.

In the present example, the distal end of blade (560) is located at aposition corresponding to an anti-node associated with resonantultrasonic vibrations communicated through flexible portion (566) ofwaveguide (580), in order to tune the acoustic assembly to a preferredresonant frequency f_(o) when the acoustic assembly is not loaded bytissue. When tissue is secured between blade (560) and clamp pad (546),the ultrasonic oscillation of blade (560) may simultaneously sever thetissue and denature the proteins in adjacent tissue cells, therebyproviding a coagulative effect with relatively little thermal spread. Insome versions, an electrical current may also be provided through blade(560) and clamp arm (544) to also cauterize the tissue.

C. Exemplary Shaft Assembly, Articulation Section, and RigidizingFeatures

Shaft assembly (530) of the present example extends distally from bodyportion (520). As best seen in FIGS. 33-34, shaft assembly (530)includes distal outer sheath (533) and a proximal outer sheath (532)that enclose the drive features of clamp arm (544) and theabove-described acoustic transmission features. Shaft assembly (530)further includes an articulation section (530), which is located at adistal portion of shaft assembly (530), with end effector (540) beinglocated distal to articulation section (630).

Articulation section (630) of the present example is configured tooperate substantially similar to articulation sections (130, 330)discussed above except for any differences discussed below. Inparticular, articulation section (630) is operable to selectivelyposition end effector (540) at various lateral deflection anglesrelative to a longitudinal axis defined by outer sheath (532).Articulation section (630) may take a variety of forms. By way ofexample only, articulation section (630) may be configured in accordancewith one or more teachings of U.S. Pub. No. 2012/0078247, the disclosureof which is incorporated by reference herein. As another merelyillustrative example, articulation section (630) may be configured inaccordance with one or more teachings of U.S. Pub. No. 2014/0005701and/or U.S. Pub. No. 2014/0114334, the disclosures of which areincorporated by reference herein. Various other suitable forms thatarticulation section (630) may take will be apparent to those ofordinary skill in the art in view of the teachings herein.

As shown in FIGS. 33-35, shaft assembly (530) further comprises a pairof articulation bands (540, 542) and a pair of translatable rods (640,642). Articulation bands (540, 542) are configured to operatesubstantially similar to articulation bands (140, 142, 340, 342)discussed above, except for any differences discussed below. Forinstance, when articulation bands (540, 542) translate longitudinally inan opposing fashion, this will cause articulation section (530) to bend,thereby laterally deflecting end effector (540) away from thelongitudinal axis of shaft assembly (530) from a straight configurationas shown in FIG. 75A to an articulated configuration as shown in FIGS.75B and 75C. In particular, end effector (540) will be articulatedtoward the articulation band (540, 542) that is being pulled proximally.During such articulation, the other articulation band (540, 542) may bepulled distally. Alternatively, the other articulation band (540, 542)may be driven distally by an articulation control. Flexible acousticwaveguide (566) is configured to effectively communicate ultrasonicvibrations from waveguide (580) to blade (560) even when articulationsection (630) is in an articulated state as shown in FIGS. 75B and 75C.

Translatable members (640, 642) are slidably disposed within theproximal portion of outer sheath (532). Translatable members (640, 642)extend longitudinally through the proximal portion of outer sheath (532)along opposite sides of outer sheath (532) and adjacent an interiorsurface of outer sheath (532). As best seen in FIG. 35, an elongaterecess (644) is formed in an exterior surface of a distal portion ofeach translatable member (640, 642). Elongate recesses (644) areconfigured to receive a proximal portion of each articulation band (540,542). Each translatable member (640, 642) further includes a pin (643)projecting outwardly from an interior surface of each elongate recess(644). An opening (641) formed in a proximal end of each articulationband (640, 642) is configured to receive a respective pin (643) oftranslatable members (640, 642). Pins (643) and openings (641) thusfunction to mechanically couple translatable members (640, 642) witharticulation bands (540, 542) such that longitudinal translation oftranslatable member (640) causes concurrent longitudinal translation ofarticulation band (540), and such that longitudinal translation oftranslatable member (642) causes concurrent longitudinal translation ofarticulation band (542).

When translatable members (640, 642) and articulation bands (540, 542)are translated longitudinally in an opposing fashion, a moment iscreated and applied to a distal end of distal outer sheath (533) in amanner similar to that described above with respect to articulationsection (130). This causes articulation section (630) and narrowedsection (564) of flexible portion (566) of waveguide (580) toarticulate, without transferring axial forces in articulation bands(540, 542) to waveguide (580) as described above. It should beunderstood that one articulation band (540, 542) may be actively drivendistally while the other articulation band (540, 542) is passivelypermitted to retract proximally. As another merely illustrative example,one articulation band (340, 342) may be actively driven proximally whilethe other articulation band (540, 542) is passively permitted to advancedistally. As yet another merely illustrative example, one articulationband (540, 542) may be actively driven distally while the otherarticulation band (540, 542) is actively driven proximally. Varioussuitable ways in which articulation bands (540, 542) may be driven willbe apparent to those of ordinary skill in the art in view of theteachings herein.

As shown in FIGS. 33-34, 51-53, 70-72, and 74A-74B, shaft assembly (530)further comprises a rod member (740) slidably disposed within theproximal portion of outer sheath (532). As will be described in moredetail below, rod member (740) is operable to translate between aproximal longitudinal position (FIG. 74B) in which rod member (740) ispositioned proximally of articulation section (630), and a distallongitudinal position (FIG. 74A) in which rod member (740) extendsthrough articulation section (630) and thereby prevents rigidizesarticulation section (740).

As shown in FIGS. 31-32, a rotation knob (531) is secured to a proximalportion of proximal outer sheath (532). Rotation knob (531) is rotatablerelative to housing (522), such that shaft assembly (530) is rotatableabout the longitudinal axis defined by outer sheath (532), relative tobody portion (520). Such rotation may provide rotation of end effector(540), articulation section (630), and shaft assembly (530) unitarily.Of course, rotatable features may simply be omitted if desired.

D. Exemplary Articulation Control Assembly

FIGS. 36-75C show the components and operation of an articulationcontrol assembly (700) that is configured to provide control forarticulation of articulation section (630). Articulation controlassembly (700) of this example comprises a motor (702) and a bevel gear(704). Motor (702) is secured within an upper portion of housing (522)of body portion (520). As best seen in FIG. 38, motor (702) is orientedobliquely relative to shaft assembly (530) such that an axle (703) ofmotor (702) is configured to rotate about an axis that is oblique to thelongitudinal axis defined by shaft assembly (530). Motor (702) comprisesa button (706) that is configured to selectively cause motor (702) torotate axle (703) is a first direction and in a second direction. Asbest seen in FIG. 38, bevel gear (704) is mechanically coupled with axle(703) of motor (702) such that rotation of axle (703) causes concurrentrotation of bevel gear (704). Bevel gear (704) includes a plurality ofteeth (710). As will be described in more detail below, rotation ofbevel gear (704) by motor (702) will cause articulation of articulationsection (630). In some alternative versions, motor (702) and bevel gear(704) are replaced with a manually rotatable knob and bevel gear similarto knob (402) and bevel gear (404) described above.

As best seen in FIG. 41, articulation control assembly (700) furthercomprises a drive assembly (720). Drive assembly (720) is secured to aproximal portion of proximal outer sheath (532). Drive assembly (720) isfurther rotatably disposed within rotation knob (531) such that rotationknob (531) is configured to rotate independently about drive assembly(720) to thereby cause rotation of shaft assembly (530) without causingrotation of drive assembly (720).

As shown in FIGS. 41A-42, drive assembly (720) comprises a proximalhousing (730), a distal housing (735), a plurality of lead screws (750,760, 770), and a cylindrical guide (780). Distal housing (735) andproximal housing (730) are coupled to one another via a plurality ofinterlocking tabs (769) and slots (767) such that rotation of proximalhousing (730) causes concurrent rotation of distal housing (735).Proximal housing (730) is also coupled with an output flange (936) of agear reduction assembly (900) through engagement between tabs (769) andslots (938), as will be described in greater detail below, such thatrotation of output flange (936) causes concurrent rotation of proximalhousing (730). Distal housing (735), proximal housing (730), and gearreduction assembly (900) substantially encompass the internal componentsof drive assembly (720) as will be described in more detail below.

FIGS. 41B-41J show gear reduction assembly (900) in greater detail. Gearreduction (900) assembly of the present example comprises a bevel gear(910), a fixed spline member (920), and a flex spline member (930). Asbest seen in FIG, 41C, bevel gear (910), fixed spline member (920), andflex spline member (930) are all coaxially aligned with each other andprovide clearance for waveguide (580) and the proximal portions of therest of shaft assembly (530) to be coaxially disposed therethrough. Asbest seen in FIGS. 41D-41E, bevel gear (910) comprises an array of bevelgear teeth (912) and an output shaft (914). Bevel gear teeth (912) areconfigured and positioned to mesh with teeth (710) of bevel gear (704)such that rotation of bevel gear (704) causes concurrent rotation ofbevel gear (910). In other words, activation of motor (702) will causerotation of bevel gear (910). As best seen in FIG. 41E, output shaft(914) has an outer surface with an elliptical profile. This allowsoutput shaft (914) to act as a wave generator within gear reductionassembly (900) as will be described in greater detail below.

FIGS. 41F-41G show fixed spline member (920) in greater detail. Fixedspline member (920) comprises a rigid cylindraceous body (922) with anarray of internal teeth (924) and an outwardly extending annular flange(926). Flange (926) is fixedly secured to housing (522) of body portion(520) such that fixed spline member (920) is configured to remainstationary within body portion (520). FIGS. 41H-41I show flex splinemember (930) in greater detail. Flex spline member (930) comprises a setexternal teeth (932) positioned at a proximal end of a cylindraceousbody (934). Body (934) is configured to deform radially outwardly yet isalso configured to rigidly transfer rotation along the length of body(934). Various suitable materials and configurations that may be used toprovide such radial flexing combined with rigid torque transfer will beapparent to those of ordinary skill in the art in view of the teachingsherein. Output flange (936) is positioned at the distal end of body(934). As noted above, output flange (936) includes an array of slots(938) that receive tabs (769) of proximal housing (730), such thatrotation of flex spline member (930) causes concurrent rotation ofproximal housing (730).

As best seen in FIG. 41J, teeth (932) of flex spline member (930) areconfigured and positioned to mesh with teeth (924) of rigid splinemember (920). At any given moment, only some of teeth (932) are engagedwith teeth (924). By way of example only, rigid spline member (930) maybe configured to have at least two more teeth (924) than flex splinemember (930). As also best seen in FIG. 41J, the elliptical outersurface of output shaft (914) of bevel gear (910) bears against theinner surface (935) of body (934) of flex spline member (930). Inparticular, the elliptical outer surface of output shaft (914) bearsagainst inner surface (935) at the antipodal points of the major axis ofthe elliptical outer surface of output shaft (914). Thus, as bevel gear(910) is rotated, the points of contact between bevel gear (910) andflex spline member (930) orbit about the central longitudinal axis ofgear reduction assembly (900). This causes teeth (932) to engage teeth(924) in orbital paths about the central longitudinal axis of gearreduction assembly (900), with body (934) flexibly deforming to providethis engagement between teeth (924, 932). Rigid spline member (920)remains stationary while flex spline member (930) rotates during suchengagement. The rotation of flex spline member (930) provides rotationof proximal housing (730) as noted above. Proximal housing (730) thusrotates in response to rotation of bevel gear (910).

It should be understood from the foregoing that activation of motor(702) will cause rotation of housings (730, 735) via gear reductionassembly (900). It should also be understood that gear reductionassembly (900) provides a strain wave gearing system or harmonic drivesystem. By way of example only, gear reduction assembly (900) may befurther configured and operable in accordance with at least some of theteachings of U.S. Pat. No. 2,906,143, entitled “Strain Wave Gearing,”issued Sep. 29, 1959, the disclosure of which is incorporated byreference herein. In the present example, gear reduction assembly (900)provides a gear reduction of approximately 25:1. Alternatively, anyother suitable gear reduction may be provided.

As shown in FIGS. 44-47, proximal housing (730) includes internalthreading (733) formed in an interior surface of proximal housing (730).As shown in FIGS. 54-58, distal housing (735) includes proximal internalthreading (910) formed in an interior surface of distal housing (735);and distal internal threading (737) formed in the interior surface ofdistal housing (735). Threadings (736, 737) have opposing pitch anglesor orientations in this example. In other words, the pitch orientationof threading (910) is opposite to the pitch orientation of threading(737). As should be understood by comparing FIGS. 46, 47, 57, and 58, aproximal portion (733A) of threading (733) of proximal housing (730) hasa greater pitch angle than a distal portion (733B) of threading (733) aswell as threadings (736, 737) of distal housing (735). As will bedescribed in more detail below, this difference in pitch angles iscauses a variance in the speed of longitudinal translation of rod member(740).

As shown in FIGS. 48-50, a first lead screw (750) includes a pair ofwedge-shaped projections (751) extending outwardly from radiallyopposing sides of first lead screw (750). First lead screw (750) furtherincludes a discrete exterior thread (754) projecting outwardly from anexterior surface of projection (751). Thread (754) is configured toengage with threading (733) of proximal housing (730). The pitch angleof thread (754) complements the pitch angle of threading (733). As willbe described in greater detail below, articulation control assembly(700) is configured to permit lead screw (750) to slide longitudinallywithin drive assembly (720) yet prevent lead screw (750) from rotatingwithin drive assembly (720). It should therefore be understood thatrotation of proximal housing (730) in a first direction will drive leadscrew (750) proximally; and rotation of proximal housing (730) in asecond direction will drive lead screw (750) distally.

As shown in FIGS. 59-61, a second lead screw (760) includes a pair ofsemi-cylindrical flanges (761) extending from radially opposing sides ofan annular body (763). Second lead screw (760) further includes adiscrete exterior thread (762) projecting outwardly from an exteriorsurface of flange (761). Thread (762) is configured to engage withproximal internal threading (910) of distal housing (735). As shown inFIGS. 62-64, a third lead screw (770) includes a pair ofsemi-cylindrical flanges (771) extending from radially opposing sides ofan annular body (773). Second lead screw (770) further includes adiscrete exterior thread (772) projecting outwardly from an exteriorsurface of flange (771). Thread (772) is configured to engage withdistal internal threading (737) of distal housing (735). The pitch angleof thread (762) complements the pitch angle of threading (910); whilethe pitch angle of thread (772) complements the pitch angle of threading(737). As will be described in greater detail below, articulationcontrol assembly (700) is configured to permit lead screws (760, 770) toslide longitudinally within drive assembly (720) yet prevent lead screws(760, 770) from rotating within drive assembly (720). It shouldtherefore be understood that, due to the opposing pitch angles ofthreading (736, 737), rotation of distal housing (735) in a firstdirection will drive lead screw (760) distally while simultaneouslydriving lead screw (770) proximally; and rotation of distal housing(735) in a second direction will drive lead screw (760) proximally whilesimultaneously driving lead screw (770) distally.

As best seen in FIG. 60, a pair of semi-circular gaps (765) are definedbetween an interior surface of each flange (761) and an exterior surfaceof annular body (763) of second lead screw (760). As best seen in FIG.63, a pair of semi-circular gaps (775) are defined between an interiorsurface of each flange (771) and an exterior surface of annular body(773) of second lead screw (770). As best seen in FIG. 42, cylindricalguide (780) is positioned within housings (730, 735) about the proximalportion of outer sheath (532). As shown in FIG. 43, a proximal end ofcylindrical guide (780) comprises a structural frame (782). Structuralframe (782) of cylindrical guide (780) is configured to be fixedlysecured within the interior of housing (522) of body portion (520) suchthat cylindrical guide (780) is configured to remain stationary withinbody portion (520).

Cylindrical guide (780) comprises a plurality of longitudinal slots(784) formed by a plurality of elongate sidewalls (786) of cylindricalguide (780). In particular, a first pair of longitudinal slots (784A) isformed in radially opposing sides of a sidewall of cylindrical guide(780), and a second pair of longitudinal slots (784B) is formed inradially opposing sides of a sidewall of cylindrical guide (780). Asshown in FIG. 25, projections (751) of first lead screw (750) areconfigured to be received within longitudinal slots (784A) ofcylindrical guide (780) such that first lead screw (750) is slidablydisposed along longitudinal slots (784A). Thus, lead screw (750) isoperable to translate within proximal housing (730) but is preventedfrom rotating within proximal housing (730).

As best seen in FIGS. 70 and 71, longitudinal sidewalls (786) ofcylindrical guide (780) are configured to be received within gaps (765)of second lead screw (760) such that lead screw (760) is slidablydisposed along cylindrical guide (780) within distal housing (735). Asbest seen in FIG. 72, longitudinal sidewalls (786) of cylindrical guide(780) are configured to be received within gaps (775) of third leadscrew (770) such that lead screw (770) is slidably disposed alongcylindrical guide (780) within distal housing (735). Thus, lead screws(760, 770) are operable to translate within distal housing (735) but areprevented from rotating within distal housing (735).

As shown in FIGS. 51 and 52, first lead screw (750) is secured to aproximal end of rod member (740) via a tensioner (756). As shown inFIGS. 65-68, tensioner (756) includes a first threaded member (756A) anda second threaded member (756B). Threaded members (756A, 756B)threadably engage one another such that a longitudinal position ofthreaded members (756A, 756B) relative to one another may be changed byrotation of first threaded member (756A) and/or second threaded member(756B). An exterior surface of first threaded member (756A) of tensioner(756) is secured to an interior surface of a through-bore (755) of firstlead screw (750) such that longitudinal translation of first lead screw(750) causes concurrent longitudinal translation of tensioner (756). Asbest seen in FIG. 52, a key (757) of second threaded member (756B) oftensioner (756) is positioned within a mating slot (747) formed in theproximal end of rod member (740) such that longitudinal translation offirst lead screw (750) causes current longitudinal translation of rodmember (740). Thus, in the present version, first lead screw (750) isoperable to both push rod member (740) distally and pull rod member(740) proximally, depending on which direction proximal housing (730) isrotated. Other suitable relationships will be apparent to those ofordinary skill in the art in view of the teachings herein.

As shown in FIG. 69, a proximal end of each translatable rod (640, 642)includes a slot (648, 649) formed therein. As shown in FIG. 70, secondlead screw (760) is secured to a proximal end of translatable rod (642)via a tensioner (756). An exterior surface of a first threaded member(756A) of tensioner (756) is secured to an interior surface of annularbody (763) of second lead screw (760) such that longitudinal translationof second lead screw (760) causes concurrent longitudinal translation oftensioner (756). A key (757) of second threaded member (756B) oftensioner (756) is positioned within mating slot (648) of translatablerod (642) such that longitudinal translation of second lead screw (760)causes current translation of translatable rod (642). Thus, in thepresent version, second lead screw (760) is operable to both pushtranslatable rod (642) distally and pull translatable rod (642)proximally, depending on which direction distal housing (735) isrotated. Because translatable member (642) is mechanically coupled witharticulation band (542), it should be understood that second lead screw(760) is operable to both push articulation band (542) distally and pullarticulation band (542) proximally, depending on which direction distalhousing (735) is rotated. Other suitable relationships will be apparentto those of ordinary skill in the art in view of the teachings herein.

As shown in FIG. 72, third lead screw (770) is secured to a proximal endof translatable rod (640) via a tensioner (756). An exterior surface ofa first threaded member (756A) of tensioner (756) is secured to aninterior surface of annular body (773) of third lead screw (770) suchthat longitudinal translation of third lead screw (770) causesconcurrent longitudinal translation of tensioner (756). A key (757) ofsecond threaded member (756B) of tensioner (756) is positioned withinmating slot (649) of translatable rod (640) such that longitudinaltranslation of third lead screw (770) causes current translation oftranslatable rod (640). Thus, in the present version, third lead screw(770) is operable to both push translatable rod (640) distally and pulltranslatable rod (640) proximally, depending on which direction distalhousing (735) is rotated. Because translatable member (640) aremechanically coupled with articulation band (540), it should beunderstood that second lead screw (760) is operable to both pusharticulation band (540) distally and pull articulation band (540)proximally, depending on which direction distal housing (735) isrotated. Other suitable relationships will be apparent to those ofordinary skill in the art in view of the teachings herein.

FIGS. 73A-75C show several of the above described components interactingto bend articulation section (630) to articulate end effector (540).FIGS. 73A, 74A, and 75A correspond to one another. In FIG. 74A, rodmember (740) is in the distal longitudinal position and therebyrigidizes articulation section (730). In FIG. 75A, articulation section(630) is in a substantially straight configuration. Then, housings (730,735) are rotated by motor (702) via gear reduction assembly (900). Therotation of housings (730, 735) causes first lead screw (750) totranslate proximally within proximal housing (730), second lead screw(760) to translate distally within distal housing (735), and third leadscrew (770) to advance proximally within distal housing (735). Thisproximal translation of first lead screw (750) is caused by rotation offirst lead screw (750) within proximal portion (733A) of threading(733). As discussed above, the greater pitch angle of proximal portion(733A) causes a greater rate of translation of first lead screw (750) ascompared with the translation rate of lead screws (760, 770), as will beunderstood by comparing FIGS. 73A-73C. The proximal translation of firstlead screw (750) pulls rod member (740) proximally in to the proximallongitudinal position as shown in FIG. 74B.

The proximal translation of third lead screw (770) pulls articulationband (540) proximally via translatable rod (640), which causesarticulation section (630) to start bending as shown in FIG. 75B. Thisbending of articulation section (630) pulls articulation band (542)distally. The distal advancement of second lead screw (760) in responseto rotation of distal housing (735) enables articulation band (542) andtranslatable rod (642) to advance distally. In some other versions, thedistal advancement of second lead screw (760) actively drivestranslatable rod (642) and articulation band (542) distally. As theoperator continues rotating housings (730, 735) via motor (702) and gearreduction assembly (900), the above described interactions continue inthe same fashion, resulting in further bending of articulation section(630) as shown in FIG. 75C. It should be understood that rotatinghousings (730, 735) in the opposite direction will cause articulationsection (630) return to the straight configuration shown in FIG. 75A;and rod member (740) to return to the distal longitudinal position tothereby rigidize the straightened articulation section (730).

The angles of threading (733, 736, 737, 754, 762, 772) are configuredsuch that articulation section (630) will be effectively locked in anygiven articulated position, such that transverse loads on end effector(540) will generally not bend articulation section (630), due tofriction between threading (733, 736, 737, 754, 762, 772). In otherwords, articulation section (630) will only change its configurationwhen housings (730, 735) are rotated. While the angles of threading maysubstantially prevent bending of articulation section (630) in responseto transverse loads on end effector (540), the angles may still provideready rotation of housings (730, 735) to translate lead screws (750,760, 770). By way of example only, the angles of threading (733, 736,737, 754, 762, 772) may be approximately +/−2 degrees or approximately+/−3 degrees. Other suitable angles will be apparent to those ofordinary skill in the art in view of the teachings herein. It shouldalso be understood that threading (733, 736, 737, 754, 762, 772) mayhave a square or rectangular cross-section or any other suitableconfiguration.

In some versions, housings (730, 735) include a visual indicator that isassociated with articulation section (630) being in a substantiallystraight configuration. Such a visual indicator may align with acorresponding visual indicator on rotation knob (531) and/or body (822)of body portion (520). Thus, when an operator has rotated housings (730,735) to make articulation section (630) approach a substantiallystraight configuration, the operator may observe such indicators toconfirm whether articulation section (630) has in fact reached asubstantially straight configuration. By way of example only, this maybe done right before instrument (500) is withdrawn from a trocar toreduce the likelihood of articulation section (630) snagging on a distaledge of the trocar. Of course, such indicators are merely optional.

E. Exemplary Alternative Rigidizing Features

FIGS. 76-80A show components of an exemplary alternative shaft assembly(830) comprising an elongate tube member (850) and a tubular guidemember (860) that may be readily incorporated into instrument (10, 200)in order to selectively rigidize articulation section (130, 330) whenarticulation section (130, 330) is in a straight, non-articulatedconfiguration. Tube member (850) and guide member (860) may also beincorporated into instrument (500) as a substitute for rod member (740)and associated components to selectively rigidize articulation section(630) when articulation section (630) is in a straight, non-articulatedconfiguration. In the present example, tube member (850) and guidemember (860) are shown as selectively rigidizing an articulation section(831), which may otherwise be configured and operable just likearticulation sections (130, 330, 630) described above.

Elongate tube member (850) of the present example comprises asemi-circular tongue (852) extending proximally from a proximal end ofelongate tube member (850). As best seen in FIG. 77, tongue (852)includes a pawl (854) projecting inwardly and downwardly from aninterior surface of tongue (852). As will be described in more detailbelow, elongate tube member (850) is longitudinally translatable along alength of shaft assembly (830) between a distal longitudinal position(FIGS. 79A and 80A) and a proximal longitudinal position (FIGS. 79C and80C). In the distal position, elongate tube member (850) is positionedabout articulation section (831) to thereby rigidize articulationsection (831). In the proximal position, elongate tube member (850) islocated proximally of articulation section (831) and thereby permitsarticulation of articulation section (831). Elongate tube member (850)of the present example is resiliently biased distally toward the distallongitudinal position. Various suitable ways in which elongate tubemember (850) may be biased distally toward the distal longitudinalposition will be apparent to those of ordinary skill in the art in viewof the teachings herein.

Elongate tube member (850) is configured to slidably and rotatablyreceive tubular guide member (860) such that elongate tube member (850)is operable to translate along a length of tubular guide member (860)and such that tubular guide member (860) is operable to rotate withinelongate tube member (850). However, while elongate tube member (850) isconfigured to translate along a length of tubular guide member (860),elongate tube member (850) is not configured to rotate about tubularguide member (860). In other words, elongate tube member (850) isconfigured to remain in a single rotational position. As shown in FIG.78, tubular guide member (860) includes an oval-shaped cam channel (862)that is formed in a sidewall of tubular guide member (860). Cam channel(862) is oriented obliquely relative to the longitudinal axis of tubularguide member (860). Cam channel (862) is configured to slidably receivepawl (854) of elongate tube member (850). As will be described in moredetail below, pawl (854) serves as a cam follower such that rotation oftubular guide member (860) within elongate tube member (850) causestranslation of elongate tube member (850) as pawl (854) translateswithin cam channel (862) of tubular guide member (860). As best seen inFIG. 78, a proximal portion (862A) of cam channel (862) comprises adetent (864) formed in distal interior surface of cam channel (862). Aswill be described in more detail below, detent (864) is configured toreceive pawl (854) to selectively maintain the position of pawl (854)within oval-shaped cam channel (862).

FIGS. 79A-80C show several of the above described components interactingto provide rigidity to articulation section (831) and/or to preventinadvertent deflection of end effector (840) relative to outer sheath(832). In FIGS. 79A and 80A, articulation section (831) is in asubstantially straight configuration and elongate tube member (850)covers articulation section (831), thereby rigidizing articulationsection (831). Then, tubular guide member (860) is rotated about thelongitudinal axis of shaft assembly (830), which causes elongate tubemember (850) to translate proximally as pawl (854) travels along camchannel (862) as shown in FIG. 79B. This proximal translation ofelongate tube member (850) exposes a portion of articulation section(831) as shown in FIG. 80B. As the operator continues rotating tubularguide member (860) about the longitudinal axis of shaft assembly (830)as shown in FIG. 79C, the above described interactions continue in thesame fashion, resulting in further proximal translation of elongate tubemember (850) due to engagement of pawl (854) in cam channel (862) untilpawl (854) engages detent (864). As shown in FIG. 80C, this furtherproximal translation of elongate tube member (850) completely exposesarticulation section (831) such that articulation section (831) may bearticulated. It should be understood that further rotation of tubularguide member (860) in the same direction (or reversal of rotation oftubular guide member (860)) will cause distal translation of elongatetube member (850) back to the distal longitudinal position shown inFIGS. 79A and 80A due to engagement of pawl (854) in cam channel (862).

It should also be understood that the receipt of pawl (854) in detent(864) may provide the operator with tactile feedback indicating thatelongate tube member (850) has reached the fully proximal position.Cooperation between pawl (854) and detent (864) may also provide somedegree of resistance to inadvertent rotation of tubular guide member(860), thereby providing some degree of resistance to distal translationof elongate tube member (850). Such resistance may be particularlydesirable in versions where elongate tube member (850) is resilientlybiased toward the distal position.

Tubular guide member (860) may be actuated in various ways. Forinstance, at least a portion of tubular guide member (860) may beexposed such that the operator may directly grasp tubular guide member(860) to rotate tubular guide member (860). As another merelyillustrative example, tubular guide member (860) may include a knob orother user input feature that the operator may grasp or otherwisemanipulate to rotate tubular guide member (860). As yet another merelyillustrative example, tubular guide member (860) may be operativelycoupled with an articulation control assembly such as articulationcontrol assembly (100, 400, 700). In some such versions, thearticulation control assembly may automatically actuate tubular guidemember (860) to drive elongate tube member (850) to the distal positionwhen articulation section (830) reaches the straight, non-articulatedconfiguration. The articulation control assembly may also automaticallyactuate tubular guide member (860) to drive elongate tube member (850)to the proximal position when the operator actuates the articulationcontrol assembly to drive articulation section (830) toward anarticulated configuration. Elongate tube member (850) may thus beactuated in a manner similar to rod member (740) described above. Stillother suitable ways in which elongate tube member (850) and/or tubularguide member (860) may be actuated will be apparent to those of ordinaryskill in the art in view of the teachings herein.

IV. Exemplary Combinations

The following examples relate to various non-exhaustive ways in whichthe teachings herein may be combined or applied. It should be understoodthat the following examples are not intended to restrict the coverage ofany claims that may be presented at any time in this application or insubsequent filings of this application. No disclaimer is intended. Thefollowing examples are being provided for nothing more than merelyillustrative purposes. It is contemplated that the various teachingsherein may be arranged and applied in numerous other ways. It is alsocontemplated that some variations may omit certain features referred toin the below examples. Therefore, none of the aspects or featuresreferred to below should be deemed critical unless otherwise explicitlyindicated as such at a later date by the inventors or by a successor ininterest to the inventors. If any claims are presented in thisapplication or in subsequent filings related to this application thatinclude additional features beyond those referred to below, thoseadditional features shall not be presumed to have been added for anyreason relating to patentability.

Example 1

An apparatus for operating on tissue, the apparatus comprising: (a) abody assembly; (b) a shaft assembly, wherein the shaft assembly extendsdistally from the body assembly, wherein the shaft assembly defines alongitudinal axis; (c) an end effector, wherein the end effector islocated at a distal end of the shaft assembly, wherein the end effectorcomprises an ultrasonic blade; (d) an articulation section, wherein thearticulation section is coupled with the shaft assembly, wherein thearticulation section is operable to articulate to thereby deflect theend effector from the longitudinal axis; and (e) an articulation controlassembly, wherein the articulation control assembly comprises: (i) afirst threaded member having a first pitch orientation, (ii) a secondthreaded member having a second pitch orientation, and (iii) anarticulation control, wherein the articulation control is configured torotate about an axis of rotation to thereby drive articulation of thearticulation section by causing translation of the first and secondthreaded members along a path that is parallel to the longitudinal axisof the shaft assembly, wherein the axis of rotation of the articulationcontrol is oriented obliquely or perpendicular to the longitudinal axisof the shaft assembly.

Example 2

The apparatus of Example 1 or any of the following Examples, wherein thearticulation section comprises: (i) a first translatable member incommunication with the first threaded member, and (ii) a secondtranslatable member in communication with the second threaded member,wherein the first translatable member and the second translatable memberare longitudinally translatable relative to each other.

Example 3

The apparatus of any of the preceding or following Examples, wherein theshaft assembly comprises an acoustic waveguide acoustically coupled withthe ultrasonic blade, wherein the acoustic waveguide has a flexibleportion, wherein the flexible portion extends through the articulationsection.

Example 4

The apparatus of any of the preceding or following Examples, wherein thearticulation control assembly further comprises a rotatable housing,wherein the rotatable housing comprises a proximal threading and adistal threading, wherein the first threaded member is engaged with theproximal threading, wherein eh second threaded member is engaged withthe distal threading, wherein the rotatable housing is configured torotate in a single direction to thereby cause translation of the firstand second threaded members in opposite directions.

Example 5

The apparatus of Example 5, wherein the articulation control comprises abevel gear, wherein the rotatable housing comprises a bevel gear,wherein the bevel gear of the articulation control is engaged with thebevel gear of the rotatable housing.

Example 6

The apparatus of any of the preceding or following Examples, wherein thebody assembly comprises a handle assembly.

Example 7

The apparatus of Example 6, wherein the handle assembly comprises: (i) apistol grip, and (ii) a trigger, wherein the trigger is pivotable towardand away from the pistol grip, wherein the articulation controlcomprises a knob positioned near the trigger such that the knob and thetrigger may both be manipulated by a single hand grasping the pistolgrip.

Example 8

The apparatus of any of the preceding or following Examples, wherein thearticulation control assembly further comprises a cylindrical guide,wherein the first threaded member and the second threaded member areoperable to translate along a length of the cylindrical guide, whereinthe cylindrical guide is configured to maintain a rotational position ofthe first threaded member and the second threaded member.

Example 9

The apparatus of any of the preceding or following Examples, wherein thearticulation control comprises an articulation knob.

Example 10

The apparatus of Example 9, wherein the articulation knob is rotatableabout an axis of rotation that is oriented perpendicular to thelongitudinal axis of the shaft assembly.

Example 11

The apparatus of any of the preceding or following Examples, wherein thearticulation control comprises an axle coupled with a motor.

Example 12

The apparatus of Example 11, wherein the axis of rotation of the axle isoriented obliquely to the longitudinal axis of the shaft assembly.

Example 13

The apparatus of any of the preceding or following Examples, wherein theapparatus further comprises a member, wherein the rigidizing member isoperable to translate relative to the articulation section to therebyselectively rigidize the articulation section.

Example 14

The apparatus of Example 13, wherein the articulation control assemblyis further operable to drive the rigidizing member.

Example 15

The apparatus of Example 13, wherein the rigidizing member is configuredto selectively translate into and out of the articulation section tothereby selectively rigidize the articulation section.

Example 16

The apparatus of Example 13, further comprising a rotatable memberhaving cam channel coupled with the rigidizing member, wherein the camchannel is rotatable about a longitudinal axis, wherein the cam channelis obliquely oriented relative to the longitudinal axis such that thecam channel is configured to drive the rigidizing member longitudinallyin response to rotation of the rotatable member about the longutidinalaxis.

Example 17

An apparatus for operating on tissue, the apparatus comprising: (a) abody assembly; (b) a shaft assembly, wherein the shaft assembly extendsdistally from the body assembly, wherein the shaft assembly defines alongitudinal axis; (c) an end effector, wherein the end effector islocated at a distal end of the shaft assembly; (d) an articulationsection, wherein the articulation section is coupled with the shaftassembly, wherein the articulation section is operable to articulate tothereby deflect the end effector from the longitudinal axis; and (e) anarticulation control assembly, wherein the articulation control assemblycomprises: (i) a proximal rotatable housing, wherein the proximalrotatable housing comprises threading, (ii) a distal rotatable housing,wherein the distal rotatable housing comprises a proximal threading anda distal threading, (iii) a first lead screw, wherein the first leadscrew is configured to threadably engage the threading of the proximalrotatable housing, wherein the first lead screw is configured totranslate to thereby limit deflection of the end effector by limitingthe flexibility of the articulation section, wherein the proximalrotatable housing is configured to rotate to thereby cause translationof the first lead screw, (iv) a second lead screw, wherein the secondlead screw is configured to threadably engage the proximal threading ofthe distal rotatable housing, and (v) a third lead screw, wherein thethird lead screw is configured to threadably engage the distal threadingof the distal rotatable housing, wherein the second lead screw and thethird lead screw are configured to translate in opposite directions tothereby drive articulation of the articulation section, wherein thedistal rotatable housing is configured to rotate in a single directionto thereby cause translation of the first lead screw and the second leadscrew in opposite directions.

Example 18

An apparatus for operating on tissue, the apparatus comprising: (a) abody assembly; (b) a shaft assembly, wherein the shaft assembly extendsdistally from the body assembly, wherein the shaft assembly defines alongitudinal axis; (c) an end effector, wherein the end effector islocated at a distal end of the shaft assembly; (d) an articulationsection, wherein the articulation section is coupled with the shaftassembly, wherein the articulation section is operable to articulate tothereby deflect the end effector from the longitudinal axis; and (e) arigidizing assembly, wherein the rigidizing assembly comprises: (i) arigidizing member, wherein the rigidizing member is configured totranslate relative to the articulation section to thereby selectivelyridigize the articulation section, and (ii) a rotatable member, whereinthe rotatable member is configured to rotate to thereby causetranslation of the rigidizing member.

Example 19

The apparatus of Example 18, wherein the rotatable member comprises alead screw.

Example 20

The apparatus of Example 18, wherein the rotatable member comprises aguide tube.

V. Miscellaneous

It should be understood that any of the versions of instrumentsdescribed herein may include various other features in addition to or inlieu of those described above. By way of example only, any of theinstruments described herein may also include one or more of the variousfeatures disclosed in any of the various references that areincorporated by reference herein. It should also be understood that theteachings herein may be readily applied to any of the instrumentsdescribed in any of the other references cited herein, such that theteachings herein may be readily combined with the teachings of any ofthe references cited herein in numerous ways. Moreover, those ofordinary skill in the art will recognize that various teachings hereinmay be readily applied to electrosurgical instruments, staplinginstruments, and other kinds of surgical instruments. Other types ofinstruments into which the teachings herein may be incorporated will beapparent to those of ordinary skill in the art.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Versions of the devices described above may have application inconventional medical treatments and procedures conducted by a medicalprofessional, as well as application in robotic-assisted medicaltreatments and procedures. By way of example only, various teachingsherein may be readily incorporated into a robotic surgical system suchas the DAVINCI™ system by Intuitive Surgical, Inc., of Sunnyvale, Calif.Similarly, those of ordinary skill in the art will recognize thatvarious teachings herein may be readily combined with various teachingsof U.S. Pat. No. 6,783,524, entitled “Robotic Surgical Tool withUltrasound Cauterizing and Cutting Instrument,” published Aug. 31, 2004,the disclosure of which is incorporated by reference herein.

Versions described above may be designed to be disposed of after asingle use, or they can be designed to be used multiple times. Versionsmay, in either or both cases, be reconditioned for reuse after at leastone use. Reconditioning may include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, someversions of the device may be disassembled, and any number of theparticular pieces or parts of the device may be selectively replaced orremoved in any combination. Upon cleaning and/or replacement ofparticular parts, some versions of the device may be reassembled forsubsequent use either at a reconditioning facility, or by an operatorimmediately prior to a procedure. Those skilled in the art willappreciate that reconditioning of a device may utilize a variety oftechniques for disassembly, cleaning/replacement, and reassembly. Use ofsuch techniques, and the resulting reconditioned device, are all withinthe scope of the present application.

By way of example only, versions described herein may be sterilizedbefore and/or after a procedure. In one sterilization technique, thedevice is placed in a closed and sealed container, such as a plastic orTYVEK bag. The container and device may then be placed in a field ofradiation that can penetrate the container, such as gamma radiation,x-rays, or high-energy electrons. The radiation may kill bacteria on thedevice and in the container. The sterilized device may then be stored inthe sterile container for later use. A device may also be sterilizedusing any other technique known in the art, including but not limited tobeta or gamma radiation, ethylene oxide, or steam.

Having shown and described various embodiments of the present invention,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one of ordinary skill inthe art without departing from the scope of the present invention.Several of such potential modifications have been mentioned, and otherswill be apparent to those skilled in the art. For instance, theexamples, embodiments, geometrics, materials, dimensions, ratios, steps,and the like discussed above are illustrative and are not required.Accordingly, the scope of the present invention should be considered interms of the following claims and is understood not to be limited to thedetails of structure and operation shown and described in thespecification and drawings.

1-20. (canceled)
 21. An ultrasonic surgical device, comprising: (a) afirst assembly including a body configured to receive an ultrasonictransducer; and (b) a second assembly configured to removably connect tothe first assembly, the second assembly, including: (i) a shaft assemblydefining a longitudinal axis and including an acoustic waveguideconfigured to removably connect to the ultrasonic transducer, (ii) anend effector distally projecting from the shaft assembly, (iii) anarticulation section coupled with the shaft assembly and configured toarticulate to thereby deflect the end effector relative to thelongitudinal axis, and (iv) an articulation control assembly operativelyconnected to the articulation section and including a drive feature,wherein the drive feature is configured to rotate about an axis ofrotation to thereby drive articulation of the articulation section,wherein the axis of rotation of the articulation control is orientedobliquely or perpendicular to the longitudinal axis of the shaftassembly.
 22. The ultrasonic surgical device of claim 21, wherein thearticulation control assembly further includes: (A) a first threadedmember and having a first pitch orientation, and (B) a second threadedmember having a second pitch orientation, wherein the drive feature isconfigured to rotate about the axis of rotation to thereby drivearticulation of the articulation section by causing translation of thefirst and second threaded members along a path that is parallel to thelongitudinal axis of the shaft assembly.
 23. The ultrasonic surgicaldevice of claim 21, wherein the first and second threaded members arecoaxially positioned.
 24. The ultrasonic surgical device of claim 21,wherein the first assembly includes an ultrasonic transducer.
 25. Theultrasonic surgical device of claim 24, wherein the ultrasonictransducer is received within the body and connected to the acousticwaveguide.
 26. The ultrasonic surgical device of claim 25, wherein thebody includes a pistol grip.
 27. The ultrasonic surgical device of claim26, wherein the second assembly further includes a trigger extendingfrom the housing.
 28. The ultrasonic surgical device of claim 21,wherein the articulation control assembly further includes a motorconfigured to connect to the drive feature for selectively rotating thedrive feature.
 29. The ultrasonic surgical device of claim 28, whereinthe motor is connected to the drive feature such that removal of thesecond assembly from the first assembly operatively disconnects themotor from the first assembly.
 30. The ultrasonic surgical device ofclaim 21, wherein the second assembly further includes a housingremovably connected to the body of the first assembly such that thehousing distally projects from the body.
 31. The ultrasonic surgicaldevice of claim 30, wherein the first assembly includes an ultrasonictransducer received within the body and connected to the acousticwaveguide, wherein the body includes a pistol grip, and wherein thesecond assembly further includes a trigger extending from the housing.32. The ultrasonic surgical device of claim 31, wherein the articulationcontrol assembly further includes a motor configured to connect to thedrive feature for selectively rotating the drive feature.
 33. Theultrasonic surgical device of claim 32, wherein the motor is positionedabove the longitudinal axis, and wherein the trigger and the pistol gripand positioned below the longitudinal axis.
 34. The ultrasonic surgicaldevice of claim 21, wherein the first assembly is a reusable assembly,and wherein the second assembly is a disposable assembly.
 35. Anultrasonic surgical device, comprising: (a) a first assembly including abody configured to receive an ultrasonic transducer; and (b) a secondassembly configured to removably connect to the first assembly, thesecond assembly, including: (i) a shaft assembly defining a longitudinalaxis and including an acoustic waveguide configured to removably connectto the ultrasonic transducer, (ii) an end effector distally projectingfrom the shaft assembly, (iii) an articulation section coupled with theshaft assembly and configured to articulate to thereby deflect the endeffector relative to the longitudinal axis, and (iv) an articulationcontrol assembly operatively connected to the articulation section andincluding: (A) a motor, and (B) an axel couple with the motor, whereinthe axel is configured to rotate about an axis of rotation to therebydrive articulation of the articulation section.
 36. The ultrasonicsurgical device of claim 35, wherein the motor is coupled to the axelsuch that removal of the second assembly from the first assemblyoperatively disconnects the motor from the first assembly.
 37. Theultrasonic surgical device of claim 36, wherein the second assemblyfurther includes a housing removably connected to the body of the firstassembly such that the housing distally projects from the body.
 38. Theultrasonic surgical device of claim 37, wherein the first assemblyincludes an ultrasonic transducer received within the body and connectedto the acoustic waveguide, wherein the body includes a pistol grip, andwherein the second assembly further includes a trigger extending fromthe housing.
 39. The ultrasonic surgical device of claim 38, wherein themotor is positioned above the longitudinal axis, and wherein the triggerand the pistol grip and positioned below the longitudinal axis.
 40. Anultrasonic surgical device, comprising: (a) a first assembly configuredto removably connect to a second assembly, the first assembly,including: (i) a shaft assembly defining a longitudinal axis andincluding an acoustic waveguide configured to removably connect to theultrasonic transducer, (ii) an end effector distally projecting from theshaft assembly, (iii) an articulation section coupled with the shaftassembly and configured to articulate to thereby deflect the endeffector relative to the longitudinal axis, and (iv) an articulationcontrol assembly operatively connected to the articulation section andincluding: (A) a motor, and (B) an axel couple with the motor, whereinthe axel is configured to rotate about an axis of rotation to therebydrive articulation of the articulation section.